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View Full Version : I FINALLY Understand... Bokeh & Aperture Roundness



Old-N-Feeble
2-Apr-2012, 12:56
It finally "clicked" in my diseased old brain.

I've often pondered the elusive "creaminess" of the out-of-focus areas of some lenses. What appeals strongly to me are sharp highly corrected high-contrast lenses with lots of aperture blades. None of my modern lenses have such an aperture. They all have the typical out-of-round apertures.

I DO realize there are other qualities that differentiate modern lenses from classic but... it's ONLY the round apertures that interest me.

Are there modern shutters into which I can transfer my #0, #1, and #3 sized cells? I realize I'll need new scales. That's okay.

BTW, I don't need flash sync.

E. von Hoegh
2-Apr-2012, 13:18
Earlier versions usually have more blades. All of the Compur shutters I have had have nice round apertures, the most recent being a mid 80s Compur 3.

Old-N-Feeble
2-Apr-2012, 13:20
Thank you... I'll search for Compur shutters.

Oren Grad
2-Apr-2012, 13:36
The shape of the aperture is far from the whole story.

http://www.trenholm.org/hmmerk/ATVB.pdf

My favorite lenses for bokeh are the Apo-Sironar-S series, in late-model Copal shutters. YMMV.

Brian C. Miller
2-Apr-2012, 13:38
You need a Bokemeter (http://photo.net/nikon-camera-forum/00aDI7?start=0), but this one only measures in micro Bokeh for 35mm. You'll need to get the Drem (makers of the Instocope) extinction bokemeter with the nine tube design and the test target. This was sold as the Glasgnademeter (glass grace meter), but its measurements correspond to over 1 giga-bokeh, which is useful for banquet format cameras and lenses.

SergeiR
2-Apr-2012, 13:44
Or you can use shutter without blades at all, and get cheap old lenses with rounding leafs and do transplants of sort... I believe it was one of Tair (old USSR) lenses that had like 21 leaf... Or just make waterhouse-like ones yourself ;) Perfect round or any shape you like (hear shaped ones were all the craze last year i believe)

E. von Hoegh
2-Apr-2012, 13:44
You need a Bokemeter (http://photo.net/nikon-camera-forum/00aDI7?start=0), but this one only measures in micro Bokeh for 35mm. You'll need to get the Drem (makers of the Instocope) extinction bokemeter with the nine tube design and the test target. This was sold as the Glasgnademeter (glass grace meter), but its measurements correspond to over 1 giga-bokeh, which is useful for banquet format cameras and lenses.

No! That's a solid-state Bokemeter. Anyone knows you need a hollow-state, AKA vacuum tube Bokemeter.


Some actually took it seriously! ( sobbing with laughter smiley)

Oren Grad
2-Apr-2012, 13:49
You need a Bokemeter (http://photo.net/nikon-camera-forum/00aDI7?start=0)

That is *delicious*. I want one. :)

Greg Miller
2-Apr-2012, 13:52
You need a Bokemeter (http://photo.net/nikon-camera-forum/00aDI7?start=0), but this one only measures in micro Bokeh for 35mm. You'll need to get the Drem (makers of the Instocope) extinction bokemeter with the nine tube design and the test target. This was sold as the Glasgnademeter (glass grace meter), but its measurements correspond to over 1 giga-bokeh, which is useful for banquet format cameras and lenses.

You should have back dated this post to April 1.

Old-N-Feeble
2-Apr-2012, 13:53
Oren... I'll studying that. I'm hoping that I can gain quite a bit by simply moving my modern lenses into shutters with very round apertures. I do realize that's not everything but I want to keep my cake and eat it too.

Others... okay... maybe I am crazy. But at least I have an excuse. My neurologist tells me so. :P

E. von Hoegh
2-Apr-2012, 13:54
Just buy a set of Dagors.

Oren Grad
2-Apr-2012, 13:56
I'm hoping that I can gain quite a bit by simply moving my modern lenses into shutters with very round apertures.

Please - save your money. You will be disappointed.

Old-N-Feeble
2-Apr-2012, 14:02
Oren... Thanks. I have lenses in #1 shutters that I can swap a modern lens into. I'll try before I buy. :)

Old-N-Feeble
2-Apr-2012, 14:03
Are post-1950 dialyte's and their variants close enough? :)


Just buy a set of Dagors.

Dan Fromm
2-Apr-2012, 14:39
Are post-1950 dialyte's and their variants close enough? :)

No no no.

Dialyte: (( )( | )( )) , where | is the diaphragm. Four air-spaced elements, eight glass-air interfaces

Dagor ()(( | ))() , where | is the diaphragm. Six elements, cemented into two triplets, four glass-air interfaces

You want a Dagor, buy a Dagor or a Dagor clone.

There are many clones, to learn about them buy a copy of A Lens Collector's Vade Mecum. Dan Colucci, who posts here as ccharrison, sells it. Cheap and worth the money.

Old-N-Feeble
2-Apr-2012, 14:44
Thank you, Dan. As usual you're post is brutal but learned, helpful and honest. I can respect that. I'll buy a copy of the Vade Mecum. :)

Does it address issues such as bokeh and aperture design?

Dan Fromm
2-Apr-2012, 15:27
No. Hokum is a modern concept largely confined to North America. The bulk of the VM was completed before the idea surfaced in its modern form.

Aperture design? What's that? To a first approximation, a hole is a hole.

Ken Lee
2-Apr-2012, 16:10
As a general proposition, the longer the lens, the greater the blur.

One way to get a peek at the blur without having to make a photo, is to point the lens at a distant white spot (a small round light bulb in a darkened room is good), and move the lens to focus closer and farther from the subject. Also tilt the lens partially away, so that the point moves away from the center of coverage. You can see what kind of aberrations that the lens produces: uneven dots with rings and ellipses versus smooth and uniform spots with soft edges.

One way to avoid having to remount all your lenses, which can be expensive and time-consuming, is to use a Sinar Copal Shutter - either by using a Sinar Camera or making an adapter for your current camera. That way, you can get barrel-mounted lenses, which usually cost less than shutter mounted lenses, and which almost always have diaphragms with many blades. The Sinar Shutter pays for itself the first time you buy a barrel-mounted lens.

For more information and sample photos, see here (http://www.kenleegallery.com/html/tech/index.php#Vintage) and here (http://www.kenleegallery.com/html/tech/index.php#Shutter).

Here's one made with a barrel-mounted 250mm Carl Zeiss Jena Tessar on 4x5. The lens was not wide-open (f/4.5) but rather around f/9: small enough to keep the subjects in focus, but wide enough to render the distance with a soft blur. That lens has 18 blades if memory serves me right: it is round at all settings.


http://www.kenleegallery.com/images/forum/sisters.jpg

Lachlan 717
2-Apr-2012, 16:12
Aperture design? What's that? To a first approximation, a hole is a hole.

And if you're shooting wide open to maximise OOF, then it's rendered moot by the iris being fully retracted.

cdholden
2-Apr-2012, 16:16
There's the Packard shutters for use with more lenses because Packard shutters vary from small to very large. They're especially good for use with slower film and/or when you have a lens that won't fit on a 5.5" Sinar board.

Oren Grad
2-Apr-2012, 16:47
Aperture design? What's that? To a first approximation, a hole is a hole.

+1. Short of contrived test targets with simple geometrical shapes, even really pathological hole shapes will have a modest effect at best on anything other than the shape of specular highlights. Pathological blur disks, OTOH...

There are all kinds of wonderful aperture shapes out there in the lens kingdom. If you're* inclined to worship classic portrait lenses, take a gander at the opening in a Studio shutter.

(* != Dan)

Dan Fromm
2-Apr-2012, 17:25
Unicum, too, I think, Oren. I just recently passed on a 120/6.8 Dagor in one. I'd swear, but could of course be mistaken, that the aperture was shaped like a cat's eye.

Frank Petronio
2-Apr-2012, 17:44
Quality bokeh may not depend as much on aperture shape as you think but if you shoot backlit enough to get flaring spots, rounded aperture spots as circles and ovals will look better than hexagonal polygonal spots.

Moopheus
2-Apr-2012, 18:00
http://www.kenleegallery.com/images/forum/sisters.jpg

I don't see any out-of-focus areas.

jp
2-Apr-2012, 18:10
There's two parts to it... One is distribution of light across the out of focus spot. A mirror lens might produce annoying rings with the light distributed primarily to the edges of the spot. An old "buttery" portrait lens might have a more gaussian distribution. A well corrected lens might have a even distribution that looks like a square wave pulse. How the light is distributed also leads to things like wires or branches turning into annoying double lines. The distribution/correction is different for foreground versus background out of focus, generally foreground is less pleasant.

The other part most people notice is the shape of the spot. This is where the many rounded blades thing comes in. I prefer a round spot over an octagonal spot or a hex spot. Sometimes those other non-rounded things can be OK to create some impressionist background where there are not bright spots that create shapes, but generally rounded spots are preferred by normal people and snobs alike. Far off center the round spots can be unround from distortion and make some nice swirliness.

Old-N-Feeble
2-Apr-2012, 18:16
Quality bokeh may not depend as much on aperture shape as you think but if you shoot backlit enough to get flaring spots, rounded aperture spots as circles and ovals will look better than hexagonal polygonal spots.


There's two parts to it... One is distribution of light across the out of focus spot. A mirror lens might produce annoying rings with the light distributed primarily to the edges of the spot. An old "buttery" portrait lens might have a more gaussian distribution. A well corrected lens might have a even distribution that looks like a square wave pulse. How the light is distributed also leads to things like wires or branches turning into annoying double lines. The distribution/correction is different for foreground versus background out of focus, generally foreground is less pleasant.

The other part most people notice is the shape of the spot. This is where the many rounded blades thing comes in. I prefer a round spot over an octagonal spot or a hex spot. Sometimes those other non-rounded things can be OK to create some impressionist background where there are not bright spots that create shapes, but generally rounded spots are preferred by normal people and snobs alike. Far off center the round spots can be unround from distortion and make some nice swirliness.

That is precisely my concern. Pinpoint lights, light, and dark out-of-focus areas all seem to look different with out-of-round apertures.

BTW, I do realize that lens design plays a big roll too. However, my wide lenses I want really W-I-D-E so I'm stuck with modern plasmats but my medium/long lenses are mostly dialytes.

Dan Fromm
2-Apr-2012, 18:19
Not to be a complete idiot, but what does the rendition of specular highlights, in- and out-of-focus have to do with the transition from in- to out-of-focus? Or, for that matter, with the dread double line bokeh?

Old-N-Feeble
2-Apr-2012, 18:27
Dan... I know nothing about "double-line bokeh". But I've looked long and hard at images and, as far as I can tell, a well-rounded aperture makes a big difference in out-of-focus areas. It's a purely pragmatic nonscientific approach, I know. I'm just trusting my tired old eyes.

Frank Petronio
2-Apr-2012, 18:28
I've had Veritos, old Brassies, and Aero Ektars, Fast 135 Xenotars, etc. what I use now is an older 1960s Linhof-Select Symmar and I like it a lot. The lens doesn't need to be super fast and shooting at f/5.6 provides enough depth of field that you don't have to worry as much as shooting more open. The rounded shutter opening makes nice spots, and the overall transition from sharp to blur is quite without being overbearing or becoming the most important part of an otherwise ordinary picture. I'm not sure if that is bokeh or if most people don't like it? I do.

IMHO most of the "portrait" and fast lenses look like mushy crap, no offense to anyone who spent a lot of money on them. And I would make an exception for one of those nice new Cookes.

In fact, I'd do your portrait in trade for a new Cooke ;-p

jp
2-Apr-2012, 18:37
Not to be a complete idiot, but what does the rendition of specular highlights, in- and out-of-focus have to do with the transition from in- to out-of-focus? Or, for that matter, with the dread double line bokeh?

I can't easily explain it for certain, but this website explains it using the very nice Nikon defocus control lenses, which require more instruction than Nikon can provide.

http://www.stacken.kth.se/~maxz/defocuscontrol/

Russ Young's soft focus lens thesis has a chapter on Bokeh too, for LF lenses, not specifically soft focus. Google it for a pdf.

jp
2-Apr-2012, 18:45
Dan... I know nothing about "double-line bokeh". But I've looked long and hard at images and, as far as I can tell, a well-rounded aperture makes a big difference in out-of-focus areas. It's a purely pragmatic nonscientific approach, I know. I'm just trusting my tired old eyes.

Here's an example you don't need tired eyes to see. I went digi-shooting with two lenses. Helios and Sigma. Sigma usually does a very nice job and makes some of the best small format lenses now for new lenses that have roundish apertures. This older sigma macro has a 6-blade aperture. Nice distribution of light through the spots, but the hex shape makes the photo look downright violent. The Helios image has things going nice and smooth primarily from the round shape. It has 13 rounded blades and looks good at any aperture.

http://jason.philbrook.us/~jp/2012/_DSC8565-004.JPG

http://jason.philbrook.us/~jp/2012/_DSC8555-002.JPG

Old-N-Feeble
2-Apr-2012, 18:50
Here's an example you don't need tired eyes to see. I went digi-shooting with two lenses. Helios and Sigma. Sigma usually does a very nice job and makes some of the best small format lenses now for new lenses that have roundish apertures. This older sigma macro has a 6-blade aperture. Nice distribution of light through the spots, but the hex shape makes the photo look downright violent. The Helios image has things going nice and smooth primarily from the round shape. It has 13 rounded blades and looks good at any aperture.

http://jason.philbrook.us/~jp/2012/_DSC8565-004.JPG

http://jason.philbrook.us/~jp/2012/_DSC8555-002.JPG

That's what I'm talking about. The first image is much easier to look at, IMHO.

rdenney
2-Apr-2012, 19:00
I have not compared large-format lenses, but I have compared small-format lenses (to include at least one adapted medium-format lens and one old large-format barrel lens).

http://www.rickdenney.com/bokeh_test.htm

It shows the effects in several situations that reveal far more than just specular highlights, though it does include those, too.

Bottom line: If you are going for a smooth, creamy background, you'll probably want lots of selective focus, which means you'll be wide open where the aperture is round with all lenses. The shape of the aperture does not affect many of the artifacts that influence subjective evaluations of bokeh. The design of the lens does. But even then, a given design family includes a lot of different design decisions that also affect bokeh. Really smooth bokeh (which is not what everyone wants by any means) seems to require a bit of undercorrected spherical aberration at wide apertures, which is not something you'll get with lenses designed to be really sharp at all apertures.

All that has a bigger effect than the aperture shape.

If you want a lens with a vintage look to the bokeh for use at wide apertures, get a tessar design, though there are exceptions (including the old B&L in my test). A cheap Ilex Paragon f/4.5, maybe 8-1/2" focal length, in an Ilex No. 4 shutter, sounds about right. The f/6.3 tessars like the Ilex-Caltar and the Kodak Commercial Ektar might be a bit too sharp, but people love them for portraits, too. Bokeh is real but it is also subjective, so there is a voyage of discovery if it's important to you. Changing only the aperture shape will not create much progress in that voyage.

Rick "who has been down that road" Denney

Oren Grad
2-Apr-2012, 19:06
Unicum, too, I think, Oren. I just recently passed on a 120/6.8 Dagor in one. I'd swear, but could of course be mistaken, that the aperture was shaped like a cat's eye.

Check out a Minox 35 sometime. It has an irregular, lozenge-shaped opening formed by the overlap of a pair of V-shaped blades. A similar design can be found in many other compact lens-shutter cameras.

Oren Grad
2-Apr-2012, 19:11
Quality bokeh may not depend as much on aperture shape as you think but if you shoot backlit enough to get flaring spots, rounded aperture spots as circles and ovals will look better than hexagonal polygonal spots.

Short of something really bizarre, I don't really care much about the shape of specular highlights. Hexagons are usually fine - even pentagons, especially if the edges bow out a bit rather than in. No doubt you could find a particularly egregious example here or there that I'd balk at, but in general it's not an issue for me.

Ken Lee
2-Apr-2012, 19:13
IMHO most of the "portrait" and fast lenses look like mushy crap, no offense to anyone who spent a lot of money on them. And I would make an exception for one of those nice new Cookes.

In fact, I'd do your portrait in trade for a new Cooke ;-p

Ditto there - I prefer a neutral blur, not an exaggerated one.

That being said, I would add to your short list of exceptions to the rule, the 9-inch Kershaw lens that Eddie lent to me (see below). Needless to say, the aperture on that lens is perfectly round.



http://www.kenleegallery.com/images/forum/Kershaw3.jpg

Oren Grad
2-Apr-2012, 19:15
Dan... I know nothing about "double-line bokeh". But I've looked long and hard at images and, as far as I can tell, a well-rounded aperture makes a big difference in out-of-focus areas. It's a purely pragmatic nonscientific approach, I know. I'm just trusting my tired old eyes.

Have you looked at the same subject rendered by the same glass using both circular and non-circular apertures?

Oren Grad
2-Apr-2012, 19:23
Not to be a complete idiot, but what does the rendition of specular highlights, in- and out-of-focus have to do with the transition from in- to out-of-focus? Or, for that matter, with the dread double line bokeh?

Dan, I suspect that it's possible to come up with instances - for example, backlit tangled branches - where polygonal features in the subject interact with the geometry of the aperture stop to exacerbate the perceptual effects of a bright-edged blur disk. But in general, I think transitions are overwhelmingly a function of the glass.

Old-N-Feeble
2-Apr-2012, 19:24
Why can't I have razor sharp images with butter smooth out-of-focus areas in the same image without having to shoot wide open or with a 100-year-old lens. I want it ALL!! :)

Old-N-Feeble
2-Apr-2012, 19:27
Oren... I've seen many examples on-line. I realize that's a limited view but of the many situations this is my objective opinion. I know of no examples which illustrate images using the same lens with both circular and non-circular irises. I'd love to see some examples though.

rdenney
2-Apr-2012, 19:38
Why can't I have razor sharp images with butter smooth out-of-focus areas in the same image without having to shoot wide open or with a 100-year-old lens. I want it ALL!! :)

Shoot medium format with a classic old Sonnar.

Rick "wishing Sonnars had better coverage and came in LF shutters" Denney

Oren Grad
2-Apr-2012, 19:40
Oren... I've seen many examples on-line. I realize that's a limited view but of the many situations this is my objective opinion. I know of no examples which illustrate images using the same lens with both circular and non-circular irises. I'd love to see some examples though.

O-N-F, human beings are really, really good at seeing patterns and correlations where there are none.

You can get silky-smooth bokeh from a modern lens in a modern shutter. That may mean something different to you than it does to me. If you insist on jumping to half-baked rules to try to short-circuit the work of taking many pictures and studying them carefully to understand how different lenses behave under different situations, there is a fair chance you will never quite find what you're looking for.

As Rick wisely said:

...there is a voyage of discovery if it's important to you.

Oren Grad
2-Apr-2012, 20:42
If you insist on jumping to half-baked rules to try to short-circuit the work of taking many pictures and studying them carefully to understand how different lenses behave under different situations...

Sorry, that was unreasonably harsh.

We all try to find simple principles to help us understand, but the OOF behavior of lenses is actually pretty complex. Many of the generalizations that are commonly seen in discussions on the topic are incorrect, or at least incomplete, or mistake subjective preference for general rule.

The upside is that if you really groove on this sort of thing, exploring lenses to calibrate your own judgment can not only help you find your way to those that best match your tastes, but can be lots of fun in itself. Being skeptical and systematic about it can help you avoid going astray. But as long as you keep your eyes open, you'll eventually figure out if you're in the wrong place anyway.

Have at it, and enjoy the trip. :)

Sal Santamaura
2-Apr-2012, 21:13
...I know of no examples which illustrate images using the same lens with both circular and non-circular irises. I'd love to see some examples though.See the 210mm Symmar Convertible results that Christopher Perez posted here:


http://www.hevanet.com/cperez/test/BigMash210.html

As an aside, when searching for the link, I noticed on Christopher's home page that the site will be taken down in June, 2012. Anyone interested in his and Kerry's large format lens tests


http://www.hevanet.com/cperez/testing.html

probably ought to save a copy before then.

paulr
2-Apr-2012, 22:22
Why can't I have razor sharp images with butter smooth out-of-focus areas in the same image without having to shoot wide open or with a 100-year-old lens. I want it ALL!! :)

Probably the only reason you can't have it is that it's not where the R&D money is going in large format lenses (if there's any money at all).

If you look at lenses for 35mm and MF digital over the last decade, there are interesting developments. It seems like the manufacturers figured out their customers were looking at the out of focus parts as well as the sharp ones. They responded.


Many of the newer lenses (small format by nikon, canon, leica, medium format by schneider, rodenstock, and leica) do exactly what you ask. The medium format digital lenses by the big three Germans are borderline miraculous. In another league from anything we've seen on other formats.

Brian C. Miller
2-Apr-2012, 22:38
Why can't I have razor sharp images with butter smooth out-of-focus areas in the same image without having to shoot wide open or with a 100-year-old lens. I want it ALL!! :)

Ask c.d.ewen here on the board for a 100-year-old lens adapted to a Copal 3 shutter. I have a Busch Rapid Aplanat that I can swap into a Copal 3, no problems. He recently completed an adaptation of a Wollensak Vesta to Ilex #5. He does an excellent job. (And unlike the modern digital lenses, the price is far, far, less than that of a new car.)

Oren Grad
2-Apr-2012, 23:33
See the 210mm Symmar Convertible results that Christopher Perez posted here:


http://www.hevanet.com/cperez/test/BigMash210.html

As an aside, when searching for the link, I noticed on Christopher's home page that the site will be taken down in June, 2012. Anyone interested in his and Kerry's large format lens tests


http://www.hevanet.com/cperez/testing.html

probably ought to save a copy before then.

Yeesh... I'll say my piece on these and then I won't belabor it.

As presented, the resolution tests are impossible to interpret. There are several sources of random and/or systematic error in these measurements:

* The use of different cameras, likely with varying errors in GG alignment
* The use of different types of GG across the different cameras, with possible variation in accuracy and precision of focus judgment
* Exposure-to-exposure variation in judgment of accurate focus on the GG, within and across observers
* The use of different film holders, likely with varying deviations from spec in T-depth
* Sheet-to-sheet slop in film position and flatness within the film holders
* Variation in subjective reading of low-contrast resolution lines on grainy magnified film, within and across observers

None of these sources of variation is tested or quantified. The magnitude of variation due to these causes could be equal to or greater than the reported lens-to-lens variation... or not. There is no way for us to know.

As for the bokeh test:

Perhaps the best realization I had in doing this test is that aperture shape influences more than just out of focus highlight shape and rendition. It defines everything about out of focus area rendition, shape, and texture.

This is conclusively refuted by countless examples of lenses that vary in rendering despite identical aperture stops. Even if that were not the case, it's also a theoretically and empirically unjustified generalization of results observed from a small selection of lenses at one point in a huge parameter space (aperture range, focus distance, subject types).

On the other hand, old lenses tend to have many many aperture blades that define a nearly round aperture shape. This is the single most important influence on out of focus area rendition.

This is a weaker claim. Even this is not justified by the observational protocol, which is not designed to assess the magnitude of these effects independently and compare them. The open aperture results provide no control, because the tested lenses all have different maximum apertures. The f/11 results as a group conflate glass and aperture variation. Some of the sources of potential error in the resolution test apply here as well.

It's hard for me to see how an image can be critically sharp in the in focus areas and creamy smooth in the out of focus areas by optical design.

Read Harold's paper, as linked above. Then go read a textbook on photographic lens design.

CCHarrison
3-Apr-2012, 03:11
I believe in Bokeh !!


71326


71327

Ken Lee
3-Apr-2012, 05:03
Oren - As always, your points are astute and sound. I guess there's such a thing as anecdotal evidence, and then there's rigorous testing. As far as I can tell, there's a spectrum of blur, with what we might call general blur at one end, and specular highlights at the other.

Here's an anecdotal test of "general blur" that I made a few years ago, with 3 different 150mm lenses at f/11: Braunschweig Heliar, APO Nikkor, and Rodentstock APO Sironar-S. 3 different designs, 3 different shutters.

Below that is another anecdotal test with 210mm Heliar, 210 Tessar, 240 Fujinon A and 240 APO Nikkor - sized to match. Four different designs, modern and older shutters. The Fujinon has a 5-bladed shutter, the Nikkor a 10-bladed shutter, and the Heliar and Tessar have so many blades that it's difficult to count them. :cool:

At f/11 - as far as I can tell - the differences in blur are inconsequential. The Heliars have a slightly stronger blur rendition, but we know that Heliars are designed with blur in mind.

That being said, I still prefer round specular highlights over pentagons, octagons, etc. and smooth ones over those with rings. These tests don't really expose those differences, but Rick's tests do. Which suggests that only certain subjects - under certain lighting conditions - will reveal the differences.

http://www.kenleegallery.com/images/forum/BokehTest150mm.png

http://www.kenleegallery.com/images/forum/BokehTest210mm.png

rdenney
3-Apr-2012, 05:23
Yeesh... I'll say my piece on these and then I won't belabor it.

I've done a lot of lens testing, just for fun. I did quantify some of those other factors (sample variation, for instance) but not all of them. But the tests are still useful representations, within appropriate caveats. In most cases, it's clear that even the oldest designs show examples that did very well in their tests, so when a newer design of a lens fulfilling the same basic objectives does poorly, then I look to other causes. I never assume that the manufacturers went backwards unless the requirements changed.

My beef with the standard resolution tests, even though I've done them, is that they don't align well with what most people want lenses to do in the real world, which is make sharp-looking prints with a lot of apparent detail. My testing became more mature as a result of that. Even so, all my testing generally supports the subjective impressions people have about those designs, when the lenses are in actual use.

On bokeh, though, I've been more careful, and learned empirically exactly what you describe in your refutation of their conclusions. My bokeh test shows examples of lenses with perfectly round apertures that form a bright edge around an out-of-focus highlight, and then compound that problem (at least it's a problem for me) with a bright spot right in the middle of the fuzzy spot.

But lots of people like the bright-edge effects, especially if they are shaped and oriented in a way that pleases them. I think it's distracting, and prefer the unfocused areas to look like they were painted by a broad, smooth brush. I'd rather the focused part of the image hold the attention of the viewer. But that is a matter of subjective taste, of course.

Paul is right that some of the newer small-format lenses are quite good. Few look to 70-200 zoom lenses on small-format cameras to have excellent bokeh, but the 70-200/4L Canon lens I use has just that, all 14 high-end elements of it. It's actually a wonderful long portrait lens, and does not depend on a having an aperture the size of a pie plate to get a smooth effect. But there's no denying its sharpness in the focus plane, at least within the context of the format.

In my strange, Second-World medium-format experience, tessar designs are thought to be sort-of clumpy looking. The magic formula there is the old Sonnar, which is a modified triplet design (unlike the tessar, which according to Kingslake was designed from the start as a four-element lens). My best example is the medium-format Jena Sonnar 180/2.8 intended for a 6x6 Pentacon. That's a fast lens in that format and focal length, to be sure, and my own testing confirms that these do not produce high MTF at tight spatial resolutions wide open. It's not chromatic aberration (which is easy to see) and it shows no evidence of coma, so one assumes the fault is (a tiny bit of) spherical aberration. That aligns with the evaluations of optical experts I've read who indicate that a bit of undercorrected spherical aberration causes those out-of-focus highlights to have a faded edge. If the edge of the fuzzy spot is faded, the shape of the aperture is hardly apparent. That faded edge also reduces double-line effects and other artifacts. But by the time the lens is stopped down to f/8 or so, the spherical aberration is corrected out and the lens produces much better contrast at higher spatial frequencies, though it's still probably not as good as a modern Oberkochen Sonnar (at the time, though, the Jena Sonnar was 10 cents on the Oberkochen dollar, and the newer lens still isn't as creamy). The lens is really well-balanced--as it is stopped down, the spherical aberration seems to be corrected out proportionately to the increase in depth of field and associated decrease in the size of the unfocused fuzzy spots. Some of my lenses are fine at f/2.8, ugly at f/5.6, and fine again at f/11 where everything becomes sharp. Not so the Sonnar.

Modern large-format lenses were designed for high-contrast resolution across a wide coverage angle, which is a tall enough challenge. I'm reasonably sure that the rendering of out-of-focus details was not a design requirement for these lenses. The way I use them, they don't need to be. But when I want a smoother rendering and a softer, calmer look to the image, I use my old, fast tessar lenses (but not that B&L that I found to produce bright edges and central spots--that lens wants to be used stopped down to make everything sharp). Even so, my regular lenses do not produce distracting out-of-focus artifacts, not even the ultra-wide designs like the Super Angulon. The plasmats are descended from dagors, and don't seem to be offensive, either. Some of the double-gauss lenses in my experience, though, can be downright crispy-fried. And I have a cheap, consumer-grade Canon zoom (35-70 or some such plastic-fantastic that I think came as the kit lens on an Elan II) that turns every specular highlight into a crescent Moon.

I've never gone the route of Velostigmats and Petzvals, or even Imagons and the like. That's not the look I want, though it sure is for lots of folks. Usually, I'm trying to make things sharp, and when they aren't, I don't want to call attention to it.

Rick "it's not about the aperture" Denney

goamules
3-Apr-2012, 06:13
I agree learning a lens' signature is a journey. When I started shooting small format, I could not see much difference at all between different lenses, be they Leica, Cannon, what have you. But as time went on, it became more apparent. Now I have preferences for sharpness, and out of focus areas. I'm still trying to learn "smoothness of tone" "drawing style", and "rendering" and other terms that sometimes feel like a lot of talk. But I have learned that bokeh is subjective. For every one who likes a smooth background, another likes a harsh, aberration-filled one.

Anyway, it may help to look at this photo test I did on three 50mm Canon lenses, the F1.2, F1.5 (sonnar), and F1.8 shot at three different apertures, here:
http://www.flickr.com/photos/garrettsphotos/sets/72157628955481717/detail/

E. von Hoegh
3-Apr-2012, 06:49
In a related vein, how many angels can dance the tarantelle in the eye of a needle?

Old-N-Feeble
3-Apr-2012, 07:11
Sorry, that was unreasonably harsh.

We all try to find simple principles to help us understand, but the OOF behavior of lenses is actually pretty complex. Many of the generalizations that are commonly seen in discussions on the topic are incorrect, or at least incomplete, or mistake subjective preference for general rule.

The upside is that if you really groove on this sort of thing, exploring lenses to calibrate your own judgment can not only help you find your way to those that best match your tastes, but can be lots of fun in itself. Being skeptical and systematic about it can help you avoid going astray. But as long as you keep your eyes open, you'll eventually figure out if you're in the wrong place anyway.

Have at it, and enjoy the trip. :)

I didn't read your post as harsh at all... just straightforward and very truthful to your beliefs. I probably am overgeneralizing and narrowly focused on one aspect of the subject. I'll learn more about it. The thing is I can't really do much testing because that would mean buying many lenses which I can't afford. Also, I don't get around very well and I really want to concentrate on making images rather than testing. If I do the latter I may never make any more images. :)

Old-N-Feeble
3-Apr-2012, 07:15
I have not compared large-format lenses, but I have compared small-format lenses (to include at least one adapted medium-format lens and one old large-format barrel lens).

http://www.rickdenney.com/bokeh_test.htm

That's a great test, Rick, and very helful!!

Old-N-Feeble
3-Apr-2012, 07:21
See the 210mm Symmar Convertible results that Christopher Perez posted here:


http://www.hevanet.com/cperez/test/BigMash210.html

Thank you, Sal. It would be great if I could find tests of differing lenses each shot wide open and stopped down to say... f/11 and f/22.

Brian C. Miller
3-Apr-2012, 07:40
See? You guys need to use a Drem Glasgnademeter to measure bokeh. That little Nikon meter just gets pegged when the LF lenses are placed on it. Plus, you need real statistics and measurements about that lens, not a one-size-fits-all number. The Leica Glasgeistometer used crystal prisms to obtain mean, standard deviation, radii, and the later versions could obtain inferential statistics as well. Unfortunately, most of these have been dismantled by new-age hippies to be used as necklaces and earrings.

E. von Hoegh
3-Apr-2012, 07:43
All we need now is a stierscheissometer. (winking smiley)

Old-N-Feeble
3-Apr-2012, 07:45
... it may help to look at this photo test I did on three 50mm Canon lenses, the F1.2, F1.5 (sonnar), and F1.8 shot at three different apertures, here:
http://www.flickr.com/photos/garrettsphotos/sets/72157628955481717/detail/

Interesting... those three Canon lenses render the test subject three completely different ways.

Old-N-Feeble
3-Apr-2012, 07:49
Brian / E. von H... I do like sarcsatic humor. If this old goat had any feelings left you'd be hurting them.:rolleyes:

E. von Hoegh
3-Apr-2012, 07:52
Brian / E. von H... If this old goat had any feelings left you'd be hurting them.:rolleyes:

Please don't take it personally.

Old-N-Feeble
3-Apr-2012, 07:59
E von H... I didn't. I'm enjoying the humor. Sorry if I didn't state that clearly. I was attempting a little sarcastic humor myself. :)

Sal Santamaura
3-Apr-2012, 07:59
Yeesh... I'll say my piece on these and then I won't belabor it...Although my post was in response to a question by the OP, I knew it would motivate an "interesting" reply from you. Just didn't expect you'd get excited enough to compose one at 2:30 AM EDT! :D

E. von Hoegh
3-Apr-2012, 08:03
E von H... I didn't. I'm enjoying the humor. Sorry if I didn't state that clearly. I was attempting a little sarcastic humor myself. :)

Oh, I got it...... (winking smiley)

Old-N-Feeble
3-Apr-2012, 08:05
Not to dilute my own thread but, regarding the "DSLR Scanner" threads, I wonder how macro lens bokeh affects the copied image(s) and if objectionable bokeh is compounded with the original taking lens. :)

E. von Hoegh
3-Apr-2012, 08:10
Not to dilute my own thread but, regarding the "DSLR Scanner" threads, I wonder how macro lens bokeh affects the copied image(s) and if objectionable bokeh is compounded with the original taking lens. :)


Well they're copying (scanning) a flat subject, so there should not be any OOFAs in the scan. But as for modifying the OOFAs presented by the original taking lens, that could be a very knotty question... is there such a thing as a digital glasscheissgeistometer?

Brian C. Miller
3-Apr-2012, 08:12
Old-N-Feeble, I really do think that lenses should be quantified, but everybody goes at it with a half-assed approach. The test targets are some haphazard arrangement of still life subjects, or trains or fence posts or whatever. At some point I'm going to take the USAF 1954 target methodology and apply it to the lenses I have. While I don't have a huge collection, I have what I figure is more than enough for me, and others can replicate it if they want.

Old-N-Feeble
3-Apr-2012, 08:32
Now that I think more on this...

It's difficult to quantify beauty... and beauty is in the eyes of the beholder. Since I haven't "beheld beauty" in a long time now, I've probably forgotten some of the ins-n-outs of the subject.;)

Bokeh is something I've never understood but I'm trying to now. Thanks to replies here and some of the provided links I can now see that lens design is just as important as aperture roundness. I really don't like edges on and sharp dots in highlights nor do I like hexagonal or octagonal ones. I like round smooth mushy ones. Out of focus shadow detail is of considerably less concern though it's important too. I still want my sharp details to be razor sharp and contrasty.

So... I gots me more lurnin' to do and, reluctantly, probably some testing of my lenses.

Oren Grad
3-Apr-2012, 09:08
See? You guys need to use a Drem Glasgnademeter to measure bokeh. That little Nikon meter just gets pegged when the LF lenses are placed on it. Plus, you need real statistics and measurements about that lens, not a one-size-fits-all number. The Leica Glasgeistometer used crystal prisms to obtain mean, standard deviation, radii, and the later versions could obtain inferential statistics as well. Unfortunately, most of these have been dismantled by new-age hippies to be used as necklaces and earrings.

I want one. :)

Oren Grad
3-Apr-2012, 09:12
Although my post was in response to a question by the OP, I knew it would motivate an "interesting" reply from you. Just didn't expect you'd get excited enough to compose one at 2:30 AM EDT! :D

Was already up too late as it was, figured what the hey, it had some entertainment value...

It's spring training. You're the batting practice pitcher. ;)

E. von Hoegh
3-Apr-2012, 09:14
Now that I think more on this...

It's difficult to quantify beauty... and beauty is in the eyes of the beholder. Since I haven't "beheld beauty" in a long time now, I've probably forgotten some of the ins-n-outs of the subject.;)

Bokeh is something I've never understood but I'm trying to now. Thanks to replies here and some of the provided links I can now see that lens design is just as important as aperture roundness. I really don't like edges on and sharp dots in highlights nor do I like hexagonal or octagonal ones. I like round smooth mushy ones. Out of focus shadow detail is of considerably less concern though it's important too. I still want my sharp details to be razor sharp and contrasty.

So... I gots me more lurnin' to do and, reluctantly, probably some testing of my lenses.

Agree 100%. Have you tried a Dagor?

rdenney
3-Apr-2012, 09:17
If you want the lens to render sharply across the focus plane, then you are pretty limited in your choices to the conventional designs that aimed at being sharp. The good news is that these haven't been sprayed by magic gold dust and tend to be more affordable. Well, except for Dagors, perhaps.

Get a fast tessar in a good portrait length as a starting point on the journey. As I suggested earlier, something like an Ilex Paragon or Kodak Ektar (not Commercial Ektar, and definitely not wide-field Ektar, which isn't a tessar at all), or maybe a Wollensak Raptar, Graflex Optar (which is the same thing), or even a Schneider Xenar or Rodenstock Ysar or Ysarex (also sold as a Type Y Caltar). These are all fastish (by LF standards) tessar designs intended for making pictures primarily of people. They have a different sort of rendering than a modern plasmat. And they are cheap. That will give you a couple of points in bokeh-space, rather than just the one you have now with your current designs. Just try one lens. If you like the rendering, keep it. If not, sell it to fund a different attempt.

I see a 210mm Osaka Commercial and a 203mm Wollensak Raptar at KEH right now. Neither are the fast tessar designs, and I would probably wait for something in the f/4.5 or 4.7 range for your purposes, but they'll give you an idea of the sorts of prices lens like these attract (low).

Rick "who has considered, even in discussions here, ways of adapting medium-format Sonnars for LF use, despite inadequate coverage" Denney

Oren Grad
3-Apr-2012, 09:21
Oren - As always, your points are astute and sound. I guess there's such a thing as anecdotal evidence, and then there's rigorous testing. As far as I can tell, there's a spectrum of blur, with what we might call general blur at one end, and specular highlights at the other.

Here's an anecdotal test of "general blur" that I made a few years ago, with 3 different 150mm lenses at f/11: Braunschweig Heliar, APO Nikkor, and Rodentstock APO Sironar-S. 3 different designs, 3 different shutters.

Below that is another anecdotal test with 210mm Heliar, 210 Tessar, 240 Fujinon A and 240 APO Nikkor - sized to match. Four different designs, modern and older shutters. The Fujinon has a 5-bladed shutter, the Nikkor a 10-bladed shutter, and the Heliar and Tessar have so many blades that it's difficult to count them. :cool:

At f/11 - as far as I can tell - the differences in blur are inconsequential. The Heliars have a slightly stronger blur rendition, but we know that Heliars are designed with blur in mind.

That being said, I still prefer round specular highlights over pentagons, octagons, etc. and smooth ones over those with rings. These tests don't really expose those differences, but Rick's tests do. Which suggests that only certain subjects - under certain lighting conditions - will reveal the differences.

Ken, thanks for these observations. There are certainly many combinations of aperture and subject configuration in which lenses with different designs will render very similarly. If those are the kinds of subjects one wants to photograph, then differences that other people get exercised about in other situations can be irrelevant. "Quality is suitability to purpose."

One challenge in sharing results on tests like these is that some distinctions that matter* - particularly in large format, where one of the main reasons to bother is subtlety in rendering - don't survive scanning and web presentation. The Apo-Sironar-S focus transition at middle apertures that I find so appealing may be impossible to show short of being in the same room and looking at prints together.

*to some people, some of the time

Oren Grad
3-Apr-2012, 09:33
Paul is right that some of the newer small-format lenses are quite good.... Modern large-format lenses were designed for high-contrast resolution across a wide coverage angle, which is a tall enough challenge. I'm reasonably sure that the rendering of out-of-focus details was not a design requirement for these lenses.

I actually have the 90mm Apo-Sironar-Digital (now relabeled as the HR Digaron-W). It's a stellar semi-wide for 6x9cm. Interestingly though, relative to your point about modern LF glass, although the cross-section of the 90 A-S-D is different, its drawing style is very reminiscent of the Apo-Sironar-S, a design that predates the explosion of interest in bokeh. I'll speculate that there's some cross-cutting design principle that Rodenstock has adopted that is helping to generate a "house style". I wonder if that's right, and if so what their optimization goals are.


In my strange, Second-World medium-format experience, tessar designs are thought to be sort-of clumpy looking.

I don't think that's strange at all. I'm not a huge tessar fan. Looking across formats, from 35mm to LF, in my experience they are highly variable in rendering but often rather on the grungy side.

Oren Grad
3-Apr-2012, 09:40
I believe in Bokeh !!


71326


71327

But drive carefully while you're believing, willya? ;)

Ken Lee
3-Apr-2012, 09:41
Duhh

I forgot to point out that the files I placed here, get considerably reduced by the forum software: they are much easier to inspect at larger size.

See http://www.kenleegallery.com/images/forum/BokehTest150mm.png

and

See http://www.kenleegallery.com/images/forum/BokehTest210mm.png

Old-N-Feeble
3-Apr-2012, 09:56
Agree 100%. Have you tried a Dagor?


No, I haven't. Maybe it's time I look for a Dagor or lens of similar design to try. I'm off to look for images made by Dagor lenses.

E. von Hoegh
3-Apr-2012, 09:57
No, I haven't. Maybe it's time I look for a Dagor or lens of similar design to try. I'm off to look for images made by Dagor lenses.

There are some in the images thread that show the signature as well as scanning will allow, but I don't know how to find them. Try borrowing one, if you can. If you like smooth "creamy" tones and interesting contrast, they might be a good choice.

Dan Fromm
3-Apr-2012, 10:09
This ignorant barbarian who doesn't appreciate the fine points is puzzled by how optical engineers can optimize for OOF rendering. What do they look at? And how, until fairly recently, did they manage to do all of the calculations needed?

To gain insight (?) into this matter I visited www.dioptrique.info, where the results of feeding many lenses' prescriptions, most taken from patents, through a ray tracing program are posted. I've looked at curves (courbes) and point images (images) for a number of lenses, can't see how to reason from them to rendering of out-of-focus anything.

Advice would be welcome.

Old-N-Feeble
3-Apr-2012, 10:13
I know that the Kodak 203mm Ektar is a dialyte design and I think I've read that the Fujinon-C series are dialyte derivitives. Generally speaking, aren't dialytes supposed to have very good bokeh?

Old-N-Feeble
3-Apr-2012, 10:16
Dan... this ignernt Texan don't speak no French. I guess I'll try every link there. :)

Oren Grad
3-Apr-2012, 10:17
I know that the Kodak 203mm Ektar is a dialyte design and I think I've read that the Fujinon-C series are dialyte derivitives. Generally speaking, aren't dialytes supposed to have very good bokeh?

I don't know dialytes. But my experience with other designs is that the optical cross-section doesn't determine the bokeh, at least not by itself. There's much variation across lenses within a given type.

Oren Grad
3-Apr-2012, 10:28
This ignorant barbarian who doesn't appreciate the fine points is puzzled by how optical engineers can optimize for OOF rendering. What do they look at? And how, until fairly recently, did they manage to do all of the calculations needed?

To gain insight (?) into this matter I visited www.dioptrique.info, where the results of feeding many lenses' prescriptions, most taken from patents, through a ray tracing program are posted. I've looked at curves (courbes) and point images (images) for a number of lenses, can't see how to reason from them to rendering of out-of-focus anything.

Advice would be welcome.

Dan, you should read Harold Merklinger's article if you haven't already. I'm sure there are more subtle corrections that enter into it as well.

Re what kind of data are informative, blur disks are telling, and I think the aberration curves can be informative as well.

Brian C. Miller
3-Apr-2012, 10:29
This ignorant barbarian who doesn't appreciate the fine points is puzzled by how optical engineers can optimize for OOF rendering. What do they look at? And how, until fairly recently, did they manage to do all of the calculations needed?

The Imagon lens was specifically designed to render an image like a human eye. There's links on the forum to some PDFs of the old advertising and user manuals. The lens wasn't designed to be used at fully opened, but stopped down to give just an "edge" of diffuseness to landscapes and such.

As for design calculations, it was all done by aliens, OK??? Humans can't do math, so aliens have to step in for all the hard parts. Slide rules and log tables and compasses and protractors are all just gimmicks and fronts to keep the unknowing from realizing that aliens have been with us since before the great pyramids and the Sphinx. No, the ancient Egyptians had no clue about the concept of the lever and inclined plane, it was all done by extraterrestrials who needed all that carved stone for a power grid system. Jules Verne tried to expose some of it, but all of it was regarded as fiction.

Dan Fromm
3-Apr-2012, 10:56
Oren, I took your advice and read the Merklinger article. Again. I'm still annoyed that he calls the image of a point source a circle of confusion. That aside, I still don't get it. In particular, I don't see which calculations are needed to estimate out of focus image quality.

Brian, when I was an undergraduate I used the CRC tables extensively. I still have a couple of analog multiplier-divider-exponentiators, also called slide rules.

I was a young research assistant before digital computers came in in a big way. I was a computer m'self, wore out a number of SCM four function electromechanical calculators; the wretched things used to expire in a thin cloud of blue smoke. I know at first hand how laborious the computations involved in ray tracing, although that's not what I did, can be. Especially when every calculation has to be checked. Labor, even that of underpaid young women and grad students, is costly. And that's why I wonder how much optimization optical engineers did in the days when the computers were a room full of young women with desk calculators.

rdenney
3-Apr-2012, 10:57
I don't know dialytes. But my experience with other designs is that the optical cross-section doesn't determine the bokeh, at least not by itself. There's much variation across lenses within a given type.

I agree, which is why if I was going to try a tessar, it would be a fast f/4.5-class design intended for people pictures, such as those made for press cameras and the like. The slower f/6.3 designs had a different purpose, it seems to me ("Commercial" suggesting "product photography"). And if I was going to praise a Sonnar, it would be an old one that still had a little residual spherical aberration that they were smart enough not to try to correct.

I suggested a tessar not so much because I think tessars make great bokeh in any absolute sense, but because they are cheap, generally useful otherwise, and provide a rendering distinctly different from modern plasmats. They always seem to me to provide a vintage look. They provide a step in the path to appreciating the distinction in one's own work, or in deciding that the distinction is not important.

Double-gauss designs do seem to fall in a class. I rarely see an image with soft transitions from the focus plane to what's out of focus with a Planar, Xenotar, or most any normal lens for small format. But often they are so fast that they produce a smooth blur by providing an overabundance of blur, so they get praised. And some get more praise than others, often by people who are justifying the price they paid, such as for that 50mm Summicron.

Probably, the double-gauss lenses are so highly corrected that the spherical aberration is, if anything, a bit over-corrected as a means of making the image seem sharper at spatial frequencies lower than ultimate resolution. I've heard optical gurus use such terms to describe Japanese normal double-gauss lenses in somewhat earlier times. I've heard people describe these as "brittle" which sort-of sounds like "oakey, with a hint of hyacinth" when describing wine. But in the former case, I think I know what they mean.

And I've never even be particularly distracted by the out-of-focus rendering of a Super Angulon, though you'd have to figure that such would not be a design goal in any way.

For Dan: I have a feeling that ray-tracing that showed a little bit of undercorrected spherical aberration at wide apertures would reveal lenses that show a faded edge on out-of-focus details. Ray-tracing is a tool that has to be applied to a set of objectives. The ray traces people have done have probably been interested in showing their focus-plane performance, though I also don't speak French and didn't follow the link. But there are articles such as this one (http://toothwalker.org/optics/bokeh.html).

And this article, which is one bit of reading in my own information store, and which shows a diagram that explains why undercorrected SA produces a soft edge, and overcorrected SA produces a hard edge:

http://bokehtests.com/Site/About_Bokeh.html

Rick "who'd love a 300mm Sonnar like the old Olympic design, but for 4x5" Denney

E. von Hoegh
3-Apr-2012, 12:11
I know that the Kodak 203mm Ektar is a dialyte design and I think I've read that the Fujinon-C series are dialyte derivitives. Generally speaking, aren't dialytes supposed to have very good bokeh?

The Artar is a Dialyte, too. Red Dots are coated, so are some made just before the RD designation was used.

Brian C. Miller
3-Apr-2012, 12:13
Labor, even that of underpaid young women and grad students, is costly. And that's why I wonder how much optimization optical engineers did in the days when the computers were a room full of young women with desk calculators.

And everybody wonders why Willie Wonka used Oompa-loompas for his work force. But what nobody remembers is that Wonka was a first-rate engineer, and all that engineering took calculations. Not only did he need to keep his secrets secret, he needed a cheaper work force. How costly is that optimization once you have a work force that works for beans, literally? When mathematics is turned into a game, your workers are so happy to do it!

Oren Grad
3-Apr-2012, 12:18
And everybody wonders why Willie Wonka used Oompa-loompas for his work force. But what nobody remembers is that Wonka was a first-rate engineer, and all that engineering took calculations. Not only did he need to keep his secrets secret, he needed a cheaper work force. How costly is that optimization once you have a work force that works for beans, literally? When mathematics is turned into a game, your workers are so happy to do it!

I want some square lenses that look round.

Struan Gray
3-Apr-2012, 13:36
I've never thought of myself as a perfectionist photographer. I certainly could never get into print perfectionism in the darkroom, and I'm happy with 'good enough' when it comes to profiling monitors and papers now. But bokeh really bugs me if it's bad. Bad for me might not be bad for you, but like all matters of taste it can be supremely important without being universal. An example I happen to have online from an earlier thread.



http://www.largeformatphotography.info/forum/attachment.php?attachmentid=8071

http://www.largeformatphotography.info/forum/attachment.php?attachmentid=8072


This is from a Hasselblad F 150 f2.8 lens, which has a perfectly round aperture wide open (top image), which becomes a non-regular ten-sided polygon once the aperture blades come into view, and then half way between f8 and f11 turns purely pentagonal (bottom image at f11). I take a lot of pictures in woods and of undergrowth and twigs, with busy backgrounds of lines and specular highlights. I avoid the pentagonal apertures.

In LF I don't insist in perfectly round apertures, but the pentagonal hole found in Copal 0 shutters is annoying. The Copal 1 aperture is heptagonal, and that works fine for me.

I discovered (and hated) longitudinal chromatic aberration (so-called "color bokeh") fairly early on in my twig obsession. It's probably the main reason I resist the siren call of high-res digital in smaller formats - a medium-long Apo-ronar on 4x5 has an effortless grace compared to the equivalent wide aperture lenses on 35 mm or APS-C.

Fashion has canonised certain lenses, but knows no logic. I like dialytes, so I get my bokeh kicks at low budget from Apo-Ronars and Ross Homocentrics instead of the more exalted Heliars and Dagors. A lot of people get all gooey and soft at the knees over triplets made asymmetric by shifting elements, but nobody buys Rodenstock Geronars or Caltar Es (modern shuttered, multicoated triplets) and unscrews the front element. Worth a try if you want soft-focus effects without flare or high prices.

Mark Sawyer
3-Apr-2012, 13:55
Regarding the Tessars, they've been produced for so many generations by so many companies for so many purposes that it's unfair to lump them together. I regard my Fuji L f/6.3, Ektar f/4.5, Velostigmat Series II f/4.5, and Carl Zeiss f/3.5 all as very different lenses, even though they're all 12-inch Tessars.

I'm of the opinion (already stated several times by others in this thread) that other than echoes of the aperture from specular highlights, the aperture doesn't contribute much to bokeh. However, if those echoes are there, it is often a very important consideration. (An important, so-far-unmentioned exception is apertures like on the Imagon and Fujinon sf lenses, where multiple perforations do significantly impact the sf effect.)

An easy experiment for someone who wants to try a round aperture in place of a non-round shutter's aperture would be to unscrew the front element, put a paper cut-out aperture in the lens, and try it both ways. Other than the echoes, I seriously doubt the most practiced eye could see any difference.

Dan Fromm
3-Apr-2012, 13:55
Struan, thanks for posting those two shots. They bring to mind some fall foliage shots (blueberry bushes from not very far away) I did a couple of years ago with a 4"/2.0 TTH Anastigmat. 6/4 double Gauss type, perfectly circular diaphragm at all apertures. Opposite result, though. At f/5.6 highlights in the background were obnoxious, at f/8 they were quite tolerable. It all depends ...

Re visual clutter in the woods, all too often I look at it, think a little, and don't shoot.

Cheers,

Dan

rdenney
3-Apr-2012, 14:10
Fashion has canonised certain lenses, but knows no logic.

What an elegant statement!

By the way, I'm not sure I agree that what creates the artifacts in the background of your f/11 image is the shape of the aperture. I think it's just as likely that the lens shifts from spherical aberration that is well corrected (and probably better corrected than the Jena Sonnar that I use, which in a heads-up comparison with a F-series Sonnar like yours does not measure up in terms of contrast and resolution, though it is still very good) to perhaps a bit of over-correction. The personality of every lens changes with aperture, it seems to me. As I said before, I have lenses that are lovely wide open, ugly at f/5.6, and lovely again at f/11. One example I can think of is a 120mm Arsat Vega, which is a double-gauss design. Aberrations and aperture seem to chasing each other, sometimes with one leading and sometimes with the other. But the shape of the aperture on that lens is never 10-sided. it's either round or hexagonal.

Rick "lenses have to be learned" Denney

rdenney
3-Apr-2012, 14:12
Re visual clutter in the woods, all too often I look at it, think a little, and don't shoot.

The woods around here all have clutter. I've been trying to think like Eliott Porter.

Rick "and maybe a bit of Jackson Pollack" Denney

Dan Fromm
3-Apr-2012, 14:25
The woods around here all have clutter. I've been trying to think like Eliott Porter.

Rick "and maybe a bit of Jackson Pollack" Denney

I try too, Rick, believe me I try. I think the NJ Pine Barrens would often defeat him too.

paulr
3-Apr-2012, 22:59
I like my twigs sharp and twiglike, but there's compelling evidence that lens engineers have indded studied blur for the occasions when they're told it's important. Here's (http://www.photozone.de/Reviews/222-nikkor-af-105mm-f2-d-dc-review--test-report?start=2) an interesting test of a small format lens that's all about minutely adjustable bokeh (god, I hate using that word, but I guess we're stuck with it). As far as I can tell, it's all about controlling the way in which the spherical aberration is (or isn't) corrected.

Once upon a time we could make generalizations about how different basic lens designs rendered things, but modern designs are anything but basic. They have to be approached on a case by case basis. It's quite counter-intuitive that a zoom lens with 18 elements, including floating and aspheric ones, could make a smoother and more organic blur than a simple old plasmat. But sudenly examples abound.

Struan, did you know that longitudinal chromatic aberration can now be corrected in software? Nikon's Capture raw processor does it, so does DXO's (the latter is supposed to be fairly miraculous, but I haven't tried it).

Oren Grad
3-Apr-2012, 23:18
bokeh (god, I hate using that word...)

Why? It's as though, out of the blue, you were to declare "god, I hate using the word 'lens'".

Brian C. Miller
3-Apr-2012, 23:50
bokeh (god, I hate using that word, but I guess we're stuck with it).

+1, I most sincerely agree. It's interesting that the Japanese word for "hits the target" hasn't entered our photographic vocabulary. Anybody know the earliest reference to bokeh? (Besides the Japanese using it, of course.)

How else would we refer to out-of-focus areas? Pictorialistic? Un-rendered? The French didn't like the American word "mall," so instead they adopted the Turkish word, "bazaar." Probably "bogey," one over par in golf, is close, but it sounds too odd to me to say, "the bogey area of a lens."

cowanw
4-Apr-2012, 03:05
The English spelling bokeh was popularized in 1997 in Photo Techniques magazine, when Mike Johnston, the editor at the time, commissioned three papers on the topic for the March/April 1997 issue; he altered the spelling to suggest the correct pronunciation to English speakers, saying "it is properly pronounced with bo as in bone and ke as in Kenneth, with equal stress on either syllable".[4] The spellings bokeh and boke have both been in use at least since 1996, when Merklinger had suggested "or Bokeh if you prefer
From Wiki


+1, I most sincerely agree. It's interesting that the Japanese word for "hits the target" hasn't entered our photographic vocabulary. Anybody know the earliest reference to bokeh? (Besides the Japanese using it, of course.)

How else would we refer to out-of-focus areas? Pictorialistic? Un-rendered? The French didn't like the American word "mall," so instead they adopted the Turkish word, "bazaar." Probably "bogey," one over par in golf, is close, but it sounds too odd to me to say, "the bogey area of a lens."

paulr
4-Apr-2012, 05:52
Why? It's as though, out of the blue, you were to declare "god, I hate using the word 'lens'".

Some words just rub me the wrong way. I also don't like the word ekphrastic, but luckily it doesn't come very often around here.

Usually when instead of bokeh I say blur, people know what I mean. And I'm less likely to hack up phlegm onto their shirt.

Old-N-Feeble
4-Apr-2012, 07:11
Okay, if folks like the word "bokeh" then why don't we just call it "X-factor"? :D

E. von Hoegh
4-Apr-2012, 07:15
Okay, if folks like the word "bokeh" then why don't we just call it "X-factor"? :D

....or we could use a term that actually conveys information, such as "out-of-focus-area". But then, everyone would understand it. That might bruise some egos.

Jay DeFehr
4-Apr-2012, 08:00
....or we could use a term that actually conveys information, such as "out-of-focus-area". But then, everyone would understand it. That might bruise some egos.

But boke doesn't refer to the out-of-focus-area itself, but a particular lens' rendition of it, and that gets cumbersome. We borrow from other languages regularly, and in the absence of a more appealing alternative, I have no problem with boke. Besides, aren't we tired of borrowing from the French?

E. von Hoegh
4-Apr-2012, 08:56
But boke doesn't refer to the out-of-focus-area itself, but a particular lens' rendition of it, and that gets cumbersome. We borrow from other languages regularly, and in the absence of a more appealing alternative, I have no problem with boke. Besides, aren't we tired of borrowing from the French?

But the French have a word that is the exact equivalent of "bokeh". It's "merde".

Old-N-Feeble
4-Apr-2012, 09:08
I don't like "merde" either. :D

E. von Hoegh
4-Apr-2012, 09:12
I don't like "merde" either. :D

But it's just as good as "bokeh". The only reason to use either term is to show that you have knowledge and experience available only to the chosen few. Very much like the annoying wine snob vocabulary, and the arrogant cigar jerk lexicon.

Oren Grad
4-Apr-2012, 09:17
Some words just rub me the wrong way. I also don't like the word ekphrastic, but luckily it doesn't come very often around here.

Usually when instead of bokeh I say blur, people know what I mean. And I'm less likely to hack up phlegm onto their shirt.

Paul, when people here start spouting gratuitous smears of contemporary photographic art, you're at pains to explain why they should keep an open mind and consider history, context and purpose to try to understand what they're seeing. You keep hammering at that despite endless provocation. More power to you! But here, where we have a technical term of craft which also has a history, context and purpose, you're out waving the pitchfork. What gives?

E. von Hoegh
4-Apr-2012, 09:35
I'm not Paul, but "bokeh" isn't a legit technical term. It's jargon, at best.

E. von Hoegh
4-Apr-2012, 09:44
Jargon. http://en.wikipedia.org/wiki/Jargon

Jay DeFehr
4-Apr-2012, 10:19
But the French have a word that is the exact equivalent of "bokeh". It's "merde".

Yes, but aren't we tired of borrowing from the French?

Jay DeFehr
4-Apr-2012, 10:24
But it's just as good as "bokeh". The only reason to use either term is to show that you have knowledge and experience available only to the chosen few. Very much like the annoying wine snob vocabulary, and the arrogant cigar jerk lexicon.

E., you're coming off cynical and defensive here. Why is this particular knowledge and experience "available only to the chosen few", as opposed to any other specific subject?

Oren Grad
4-Apr-2012, 10:25
....or we could use a term that actually conveys information, such as "out-of-focus-area". But then, everyone would understand it. That might bruise some egos.


But it's just as good as "bokeh". The only reason to use either term is to show that you have knowledge and experience available only to the chosen few. Very much like the annoying wine snob vocabulary, and the arrogant cigar jerk lexicon.

This is the exact opposite of what motivated the original articles, and of what has actually happened. When people didn't have the term "bokeh", they could have talked about out-of-focus character - but they didn't. It was an esoteric topic, the province primarily of those who were into classic soft-focus lenses. The introduction of a compact, simple and memorable term - borrowed from well-established use in Japan - made the concept more accessible, not less. It brought awareness to a much wider group, and serious discussion of the technical aspects to a smaller group, but still one that is much wider than was previously the case. Far more people know about it and far more people understand it now - not fewer. That was the purpose of the articles in PT, and they were successful in that respect.

As for the fixation on snobbery/anti-snobbery, I have no idea where that comes from. Perhaps you can explain.

rdenney
4-Apr-2012, 10:29
Usually when instead of bokeh I say blur, people know what I mean.

I say blur when I mean blur, but bokeh is the quality of the blur. It's hard to avoid jargon, like, say, indexicality (a word you defined for me), when discussing specialized topics.

Rick "better a wholly new word than a common word twisted into a term of jargon" Denney

Oren Grad
4-Apr-2012, 10:34
I say blur when I mean blur, but bokeh is the quality of the blur.

"Blur", in English usage, is also ambiguous between motion blur and defocus blur.

Brian C. Miller
4-Apr-2012, 11:04
One of my native-born and raised Japanese colleagues tells me that bokeh means blurry, out of focus. and also refers to people when they are "in a daze" or confused.

OK, so referring to a lens' "grace" or "spirit" would actually go farther in defining a lens' qualities than just a Japanese word for "blurry." (An online dictionary translated it as, "to miss the mark.")

Things which make up a lens' grace:
1. Halo
2. Blur
3. Blur point distortion (even, centered, ring)
4. Formation
5. Edge distortion

Halo would be the amount that a reflected white object would intrude into an adjacent black object.
Blur would be the amount of defocus blur, based on distance from the focus plane, and also per aperture.
Blur point distortion would be the amount of distortion of a blurred point object, measured for eveness. 0 would be neutral, negative would be a ring, and positive would be a "hot" point. This may need to be expressed with deviation.
Formation would be blur point forms, such as the hovering dots from strainer-type discs or aperture leaf patterns.
Edge distortion would be what happens at the edge of the lens coverage, including "swirlies" compression and notable drop in resolution and coverage.

-- Brian "if you think this is bad, just wait until Rick gets ahold of it" Miller

E. von Hoegh
4-Apr-2012, 11:09
This is the exact opposite of what motivated the original articles, and of what has actually happened. When people didn't have the term "bokeh", they could have talked about out-of-focus character - but they didn't. It was an esoteric topic, the province primarily of those who were into classic soft-focus lenses. The introduction of a compact, simple and memorable term - borrowed from well-established use in Japan - made the concept more accessible, not less. It brought awareness to a much wider group, and serious discussion of the technical aspects to a smaller group, but still one that is much wider than was previously the case. Far more people know about it and far more people understand it now - not fewer. That was the purpose of the articles in PT, and they were successful in that respect.

As for the fixation on snobbery/anti-snobbery, I have no idea where that comes from. Perhaps you can explain.

Snobbery is based upon a fatuous pretentious "superiority". Another form of arrogance and conceit.

If I, to a non-photographer, point out the difference (between two lenses) in out of focus rendition, they can understand what I mean. If I prattle about bokeh, they will not understand.

rdenney
4-Apr-2012, 11:12
"Blur", in English usage, is also ambiguous between motion blur and defocus blur.

Context is important. Without it, all language becomes legalese, whose practitioners believe every possible ambiguity has to be explicitly articulated. But there may be no context where "blur" means the same thing as "bokeh".

The problem with a wholly new word, of course, is that nobody has authoritatively codified its definition. "Bokeh" has attracted several definitions, which means it's subject to being defined differently than "quality of blur". On the digital forums that have threads for displaying examples of good bokeh, many of the examples show highly distracting out-of-focus backgrounds, but were made at f/1.4. Clearly, they are defining it as quantity rather than quality. If that becomes the accepted meaning, through their sheer numbers, then the term will indeed compete with "blur", however imprecise that term also is. Then, we'll need a new word to describe the quality of blur in unfocused areas (!).

Edit: I see Brian has already anticipated this issue.

Rick "thinking it was Merklinger's article in Photo Techniques where he first saw it" Denney

rdenney
4-Apr-2012, 11:27
Snobbery is based upon a fatuous pretentious "superiority". Another form of arrogance and conceit.

If I, to a non-photographer, point out the difference between two lenses in out of focus rendition, they can understand what I mean. If I prattle about bokeh, they will not understand.

This is obviously a particular sticking point for you, so probably there's no persuading. We certainly all have our sticking points.

But just to provides some examples:

"It turns out that some lenses render out of focus areas smoothly, which has been called smooth "bokeh". By "bokeh", I mean the quality of that out-of-focus blur, as it has been used in the literature in the last 15 years or so. Other lenses render bokeh with visible artifacts. Those artifacts may or may not be desirable according to the tastes and artistic intentions of the photographer."

"That photo you displayed has harsh and distracting rendition. You should get a better lens."

The first is not pretentious at all and explains itself even to a rank beginner. The second avoids the term of craft but is still arrogant and conceited.

I'm not one who believes that terms are arrogant and pretentious, though they can certainly be the tools of arrogant and pretentious people, if used to belittle the ignorant rather than educate them.

Rick "a professional explainer" Denney

Jay DeFehr
4-Apr-2012, 11:39
Snobbery is based upon a fatuous pretentious "superiority". Another form of arrogance and conceit.

If I, to a non-photographer, point out the difference (between two lenses) in out of focus rendition, they can understand what I mean. If I prattle about bokeh, they will not understand.

Perhaps if you pointed out the differences in boke, and prattled about out of focus rendition, you'd get the opposite result? Or do you think most non-photographers are incapable of incorporating a new term into their vocabulary?

Jay DeFehr
4-Apr-2012, 11:42
Sorry, Rick -- you beat me to it!

E. von Hoegh
4-Apr-2012, 11:51
This is obviously a particular sticking point for you, so probably there's no persuading. We certainly all have our sticking points.

But just to provides some examples:

"It turns out that some lenses render out of focus areas smoothly, which has been called smooth "bokeh". By "bokeh", I mean the quality of that out-of-focus blur, as it has been used in the literature in the last 15 years or so. Other lenses render bokeh with visible artifacts. Those artifacts may or may not be desirable according to the tastes and artistic intentions of the photographer."

"That photo you displayed has harsh and distracting rendition. You should get a better lens."

The first is not pretentious at all and explains itself even to a rank beginner. The second avoids the term of craft but is still arrogant and conceited.

I'm not one who believes that terms are arrogant and pretentious, though they can certainly be the tools of arrogant and pretentious people, if used to belittle the ignorant rather than educate them.

Rick "a professional explainer" Denney

Actually Rick, your examples make almost the same point I wish to.

I don't like or use the term "bokeh" because I don't like and avoid using jargon, preferring plain but exact English which can be understood by any person literate in that language. You first example also demonstrated the superfluity of "bokeh" in that the character of a lens can be discussed quite thoroughly without the jargon.

E. "who was weaned on the writing of Ambrose Bierce and Mark Twain" von Hoegh.

E. von Hoegh
4-Apr-2012, 11:54
Perhaps if you pointed out the differences in boke, and prattled about out of focus rendition, you'd get the opposite result? Or do you think most non-photographers are incapable of incorporating a new term into their vocabulary?

Even when prattling, "out of focus rendition" carries meaning, while "boke" does not.

rdenney
4-Apr-2012, 12:03
Even when prattling, "out of focus rendition" carries meaning, while "boke" does not.

It sure might get cumbersome in an article about it, however. Maybe I could write "bokeh" and then do a search-and-replace to change it with "the quality of the rendering of out-of-focus areas".

By the way, Ambrose Bierce and Mark Twain had quite a different English to work with than, say, Samuel Johnson, or John Bunyan, or William Shakespeare, or, for that matter, Chaucer or the Venerable Bede.

Given that English is and always has been a continuously emerging amalgamation of a variety of languages, I wonder why people draw a line and say all the revisions that went before are okay while all those that followed are to be shunned. But people do sure seem to be willing to fall on their swords over it.

Rick "noting that Ambrose Bierce and Mark Twain didn't have the language to describe many modern scientific and technical topics, because they didn't need it" Denney

Oren Grad
4-Apr-2012, 12:11
The problem with a wholly new word, of course, is that nobody has authoritatively codified its definition. "Bokeh" has attracted several definitions, which means it's subject to being defined differently than "quality of blur". On the digital forums that have threads for displaying examples of good bokeh, many of the examples show highly distracting out-of-focus backgrounds, but were made at f/1.4. Clearly, they are defining it as quantity rather than quality. If that becomes the accepted meaning, through their sheer numbers, then the term will indeed compete with "blur", however imprecise that term also is. Then, we'll need a new word to describe the quality of blur in unfocused areas (!).

Yes. Words take on a life of their own - there's no telling where popular usage will go. But a point of information: in Japanese, if you want to be more precise in referring to the character rather than the mere fact of blur, you say "bokeh-aji" - literally, the "flavor" of the bokeh.


"thinking it was Merklinger's article in Photo Techniques where he first saw it"

More's the pity that of the three articles plus editorial comment that made up the "bokeh" feature in PT, only Harold's article on the technical aspects is available online. The other articles provided broader context and had more to say about terminology, touching also on some of the aspects that Brian mentions.

But even at that, after the feature was published Mike's letterbox overflowed with incoherent rants from readers bothered by... we weren't always sure quite what.

E. von Hoegh
4-Apr-2012, 12:13
It sure might get cumbersome in an article about it, however. Maybe I could write "bokeh" and then do a search-and-replace to change it with "the quality of the rendering of out-of-focus areas".

By the way, Ambrose Bierce and Mark Twain had quite a different English to work with than, say, Samuel Johnson, or John Bunyan, or William Shakespeare, or, for that matter, Chaucer or the Venerable Bede.

Given that English is and always has been a continuously emerging amalgamation of a variety of languages, I wonder why people draw a line and say all the revisions that went before are okay while all those that followed are to be shunned. But people do sure seem to be willing to fall on their swords over it.

Rick "noting that Ambrose Bierce and Mark Twain didn't have the language to describe many modern scientific and technical topics, because they didn't need it" Denney

Or you could use the term "grace" or "spirit" which as has already been pointed out go farther to define the character of the OOFAs than a Japanese word which originally meant "blurry" and "confused".

E. "noting that Bierce and Twain stressed the importance of clean English, regardless of the vocabulary they had to work with" von Hoegh.

rdenney
4-Apr-2012, 12:15
Or you could use the term "grace" or "spirit" which as has already been pointed out go farther to define the character of the OOFAs than a Japanese word which originally meant "blurry" and "confused".

E. "noting that Bierce and Twain both stressed the importance of clean English, regardless of the vocabulary they had to work with" von Hoegh.

What's an OOFA?

Rick "is that smug?" Denney

E. von Hoegh
4-Apr-2012, 12:16
What's an OOFA?

Rick "is that smug?" Denney

Out Of Focus Area. See? Acronyms don't carry meaning, either.

Jay DeFehr
4-Apr-2012, 12:25
Actually Rick, your examples make almost the same point I wish to.

I don't like or use the term "bokeh" because I don't like and avoid using jargon, preferring plain but exact English which can be understood by any person literate in that language. You first example also demonstrated the superfluity of "bokeh" in that the character of a lens can be discussed quite thoroughly without the jargon.

E. "who was weaned on the writing of Ambrose Bierce and Mark Twain" von Hoegh.

So, you have a strict, No New Words policy? This is either complete crap (exact enough?), or you're comfortably ignorant of etymology and linguistics, or even the concept of a living language. Maybe you should put down the Twain and pick up a Chomsky.

E. von Hoegh
4-Apr-2012, 12:28
So, you have a strict, No New Words policy? This is either complete crap (exact enough?), or you're comfortably ignorant of etymology and linguistics, or even the concept of a living language. Maybe you should put down the Twain and pick up a Chomsky.

I'm about done with this subject. I've made myself clear (to any but the wilfully obtuse), and yes I've read Noam.

E. von Hoegh
4-Apr-2012, 12:46
E., you're coming off cynical and defensive here. Why is this particular knowledge and experience "available only to the chosen few", as opposed to any other specific subject?

It's funny, Jay. I never used the ad hominem attack on you, I merely "displayed a general garment"; you're the one who claimed it fit.

Dan Fromm
4-Apr-2012, 12:56
I’ve never bought the view that there’s something about the French language that encourages clarity, but French lens makers have spoken in their propaganda, sorry, product brochures, about lenses rendition more clearly than most of us have. My translations.

Boyer, on the Opale, an anachromatic soft focus lens, in a brochure published in the late ‘30s: ‘Objectif d’artiste, très apprécié pour le “flou – net”’ Artist’s lens, very appreciated for the “blurred – clear” (or soft – sharp)

Berthiot, in a brochure from around 1950: ‘Les objectifs Color f/4 à f/5 et Eidoscope f/4,5 exploitent les effets curieux que l’on peut tirer, chez le premier, d’un chromatism exalté, chez le second, de l’aberration sphérique, judicieusment dosée, en vue d’obtenir des images artistiques, dont le dessin s’enlève sur un fond endouci’ Our lenses Color (f/4 – f/5) and Eidoscope (f/4.5) take advantage of the interesting effects that one can obtain, with the first from enhanced chromatic aberration, and with the second from spherical aberration, judiciously applied, to obtain artistic images whose main subjects stand out from a softened background.

Both makers were much more interested in the transition from in focus to out-of-focus than in the rendition of specular highlights.

One of the difficulties I have with the term bokeh is that it includes too many effects that don’t have to be lumped together and that I’m not sure – I could be convinced … -- have the same causes.

Oren Grad
4-Apr-2012, 13:04
Or you could use the term "grace" or "spirit" which as has already been pointed out go farther to define the character of the OOFAs than a Japanese word which originally meant "blurry" and "confused".

E. "noting that Bierce and Twain stressed the importance of clean English, regardless of the vocabulary they had to work with" von Hoegh.

Your guiding principle is non-obfuscation, and so you're going to explain lens behavior to non-photographers by using the words "grace" and "spirit".

Oren Grad
4-Apr-2012, 13:09
One of the difficulties I have with the term bokeh is that it includes too many effects that don’t have to be lumped together and that I’m not sure – I could be convinced … -- have the same causes.

Dan, the problem of where to find the right balance between lumping and splitting will always be with us. The answer will be different, for different contexts and purposes.

Anyway, specular highlights, OOF backgrounds, and focus transitions are indeed three conceptually distinct things. Discussions of bokeh sometimes draw the distinction, but often not. Greater clarity on this would indeed be helpful.

Struan Gray
4-Apr-2012, 13:17
Struan, thanks for posting those two shots. They bring to mind some fall foliage shots (blueberry bushes from not very far away) I did a couple of years ago with a 4"/2.0 TTH Anastigmat. 6/4 double Gauss type, perfectly circular diaphragm at all apertures. Opposite result, though. At f/5.6 highlights in the background were obnoxious, at f/8 they were quite tolerable. It all depends ...

I see bokeh as a combination of aberrations, defocus, aperture shape, focus point and the subject in front of the camera. All contribute (and there are more, like the petal-like shapes which turn up with leaf shutters at high speeds) but if you attend to them you learn which photographic situations are more or less likely to be affected. You also learn which of your lenses do what.

I think it was Lord Rutherford who said that bad theories describe, good ones explain, and great ones make predictions. Bokeh is mostly bad theory. You can however get some predictive power by looking at spot diagrams (mise en point on the dioptrique site). These show how what would be a point of light in an ideal image will look like once focussed by a real lens. Images of stars and distant lights correspond exactly with the spot diagram for a particular angle and amount of defocus. For real objects you need to convolute the spot diagram with the ideal image.

It's the convolution that trips up the non-specialist. The process of combining ring-shaped 'bad' bokeh with a linear feature to get pairs of lines is one example of convolution, but the idea is more general. It describes nicely (at least, at the local level) how a pentagonal aperture can increase the effect of a busy background. Often in my undergrowth images the twigs which align with the sides of the aperture are emphasised, ruining the all-over, isotropic effect I usually strive for in my backgrounds.

I have backed off a bit on the twiggy stuff of late, but the visual detective in me loves the stories being told by my local sapling-dense woodlands. They are a surrogate for a ten thousand word essay on changing land use, conservation ecology, and people's strange relationship with trees. I do weeds and arable crops too now though. Bunnies and flowers on occasion.


What an elegant statement!

Aw shucks!


By the way, I'm not sure I agree that what creates the artifacts in the background of your f/11 image is the shape of the aperture. I think it's just as likely that the lens shifts from spherical aberration that is well corrected (and probably better corrected than the Jena Sonnar that I use, which in a heads-up comparison with a F-series Sonnar like yours does not measure up in terms of contrast and resolution, though it is still very good) to perhaps a bit of over-correction.

I'm sure someone can dig up an exception, but the received wisdom is that stopping down always reduces spherical aberration. You can see in the f11 picture little pentagons caused by specular highlights, as well as weird textures with flares or harsh lines following the sides of those pentagons. Both are the signature of a strong influence of aperture-shape. You can't see it, but a lot of the harshness comes in between f8 and f11.


As I said before, I have lenses that are lovely wide open, ugly at f/5.6, and lovely again at f/11.

Quite a lot of lenses benefit from a circular aperture wide open when the blades are out of the way, acquire busy backgrounds as the aperture blades appear, and then get better again as aberrations are quashed by stopping down.


"lenses have to be learned" Denney

I agree, but the parameter space is not as dauntingly large as it might at first appear.



I like my twigs sharp and twiglike, but there's compelling evidence that lens engineers have indded studied blur for the occasions when they're told it's important. Here's (http://www.photozone.de/Reviews/222-nikkor-af-105mm-f2-d-dc-review--test-report?start=2) an interesting test of a small format lens that's all about minutely adjustable bokeh (god, I hate using that word, but I guess we're stuck with it). As far as I can tell, it's all about controlling the way in which the spherical aberration is (or isn't) corrected.

Spherical aberration is important, and traditionally is a major concern in soft-focus optics, but more generally any aberration can and will contribute. Astigmatism is generally quenched mercilessly in photographic optics (there's a reason those early lenses were proudly labelled "anastigmat"). Coma is often a contributor to bad or busy bokeh, and is much more complex to analyse - and in its effects - than spherical aberration. Petzval swirlies, for example, are largely dominated by coma.


Struan, did you know that longitudinal chromatic aberration can now be corrected in software? Nikon's Capture raw processor does it, so does DXO's (the latter is supposed to be fairly miraculous, but I haven't tried it).

I haven't seen the latest and greatest. My only caveat would be that eliminating LoCa after the fact requires making assumptions about what is the subject of the photograph and what is the 'best' way to present that subject in a photograph. I often find myself disagreeing with those choices, or shooting subjects which subvert them (such as early spring brambles, which at their peak have both the standard colours of LoCa in combinations which get ruined by automatic eliminators).


A final observation on formats. I've already referred to the grace of LF optics, as the residual aberrations from trying to make a relatively slow lens cover a large negative are (IMHO) better looking than the typical effects of striving for faster apertures than f2. There is also the way that focal length, aperture and field of view interact as you move to larger formats, which leads to the absolute size of the aperture becoming a smaller and smaller proportion of the negative width. Bokeh in LF is usually a question of texture, not gross image components. The huge globular aperture shapes which dominate, say, backlit nature macros in 35 mm don't show up much in LF outside of Aero Ektar proof of concept shots.


As for names. I'm still fighting a rearguard action in favour of retaining "higher lights" for the bright bits of my photos.

Struan Gray
4-Apr-2012, 13:32
PS: much as I like Ambrose Bierce, one look at the entry for 'Photograph' in the Devil's Dictionary makes it clear that the evolution of language, and the attitudes it encodes, is not a wholly bad thing.

'Painting' and, especially, 'Picture' redeem him.

Old-N-Feeble
4-Apr-2012, 14:00
I agree with the comment that English is an ever-changing (live) language. In fact, without world-wide mass media English-speaking countries could change the language so much that we may not be able to effectively communicate between continents or even regions within our own. That's happened with many languages. Think about all the words that are considered filthy language today that, long ago, were just everyday words. At least for now, "beating the bokeh" out of someone or "bokeh hitting the fan" has no meaning. But... I'm sure those with the will and creative ferver will eventually find a way to make bokeh a dirty word. Then all the bokeh haters will have the last laugh and another word will replace it. :D

Mark Sawyer
4-Apr-2012, 14:32
But the French have a word that is the exact equivalent of "bokeh". It's "merde".

Sorry, but the French lost all photographic naming rights after "Giclée" :rolleyes:

I didn't mind "bokeh" at first, but it became an over-popularized fad-term. ("My cell phone cam has a shit-ton of bokeh!" Yes, a sentence I really heard.)

I've gone back to the pre-bokeh terms, where it was a lens' "signature" or "personality" that referred to what made it different from others.

Jay DeFehr
4-Apr-2012, 15:50
Sorry, but the French lost all photographic naming rights after "Giclée" :rolleyes:

To be fair, they did invent photography, or should I say photographie.

Oren Grad
4-Apr-2012, 16:41
I think it was Lord Rutherford who said that bad theories describe, good ones explain, and great ones make predictions. Bokeh is mostly bad theory.

This is a bit uncharitable. Can you find anybody who has argued that bokeh terminology is anything more than taxonomy? But I think this...


It's the convolution that trips up the non-specialist.

...is right. Some of the discussion up-thread amounts to a debate about how much the different inputs to a convolution influence the outputs. And the answer is, it depends. Dan is - within a sensible general inclination toward skepticism - wrestling with the question of whether and how the optical phenomena he understands in isolation add up - convolve? - to the behavior we observe.

Oren Grad
4-Apr-2012, 17:03
I haven't seen the latest and greatest. My only caveat would be that eliminating LoCa after the fact requires making assumptions about what is the subject of the photograph and what is the 'best' way to present that subject in a photograph. I often find myself disagreeing with those choices, or shooting subjects which subvert them (such as early spring brambles, which at their peak have both the standard colours of LoCa in combinations which get ruined by automatic eliminators).

Digital processing is full of traps for those who groove on optical character. Sharpening algorithms parse image data, hunting for things to construe as edges. Discrimination criteria based on difference thresholds result in selective and spatially discontinuous amplification of pixel value differences. What was that about smooth focus transitions, again? If the convolution of aperture stops and blur disks with subject content is difficult to intuit, try throwing sharpening into the mix. Caveat emptor.

rdenney
4-Apr-2012, 20:24
Digital processing is full of traps for those who groove on optical character. Sharpening algorithms parse image data, hunting for things to construe as edges. Discrimination criteria based on difference thresholds result in selective and spatially discontinuous amplification of pixel value differences. What was that about smooth focus transitions, again? If the convolution of aperture stops and blur disks with subject content is difficult to intuit, try throwing sharpening into the mix. Caveat emptor.

This matches completely with my experience. The sharpening I apply to such photos has to be at a scale very much smaller than the effects in question. Often, when that transition gets messed up by sharpening, I just don't sharpen at all. If that transition is there, it usually doesn't need sharpening.

Scanning resolution should operate at a smaller scale, and I often perform basic corrective sharpening to counteract the scanner effect, but this should be invisible at the scale of subject material. In our scanner project, we are trying to be able to scan at the grain level--that can be sharpened fully because there is no smooth signal at the frequency of the grain. Sharpening the grain fully does not undermine smoothness in a print, unless its over-enlarged, but then grain is the issue just as it would be in an optically enlarged print.

When I'm trying to present everything as sharp, then I sharpen also when I'm targeting the file to a particular print size.

Struan is right that everything influences the outcome, and that the mix of influences is mighty difficult to pin down. All models are false, but some are useful. But it is just as wrong to attribute the effects all the way to aperture shape as it is to attribute it to aberrations or some other influence. They interact, and perhaps in nonlinear ways that make prediction difficult. The differences in the effects I recorded in my article cannot be attributed to aperture shape for many of the images--the aperture was round in good and bad examples. That nice, round, 10-bladed aperture did no good with that B&L Tessar, that's for sure.

The problem with partial models is that we can only partially draw conclusions from them. A test showing that a five-sided aperture caused ugly artifacts might lead one to seek round apertures (which is where this thread started), only to find that lenses with round apertures can still have undesirable (or desirable) bokeh for other reasons. Another test demonstrating lovely bokeh from a lens with subtly undercorrected spherical aberration might lead one to look for such lenses, without realized how subtle is the effect and how tightly it is integrated with other factors.

We are left in the end pretty much where we started, at least until that bokescheissemeter (or whatever it was) becomes reality. We try lenses that others like or that made pictures we admire. If they please us, we keep using them. If not, they go back on the block. We are back to the journey, in which we might learn as much about the effect we want as we learn about lenses that produce them. The image is a superimposed stack of fuzzy spots, and figuring out how they will add up is probably most practically an empirical exercise.

Rick "and not just sharpening algorithms--compression algorithms, too" Denney

Struan Gray
5-Apr-2012, 01:17
This is a bit uncharitable. Can you find anybody who has argued that bokeh terminology is anything more than taxonomy?

The bad science comes when people give technical-sounding reasons for why their perfectly valid observations turned out the way they did. Partial explanation hardens to received wisdom which is then handed down on tablets of stone as buying advice. The most obvious example is the brand worship of particular named classic lens designs irrespective of an individual manufacturer's implementation, or an individual lens' history of drops, dings and cack-handed reassembly. For a more contemporary example, witness the gathering witchhunt against symmetric lenses on mirrorless cameras.

Some of my best friends are taxonomists. It is my personal feeling that there is not enough respect for simple observation in modern science, and I have great fondness for things like Goethe's Farbenlehre, phlogiston theory, Ptolomaic astronomy or Kelvin vortex atoms - all of which are wrong by the lights of today's canonical science, but which were founded on accurate and perceptive observation, and were useful, flexible systems of thought before the labelling set in.

Nor do I entirely discount anecdote, especially in the aggregate. I just distrust crowdsourced wisdom when most of the crowd doesn't understand the terms of reference with any degree of subtlety.

Bokeh can be fairly easily characterised. It's just tedious even for a single lens, and at the build quality and price point of conventional photographic optics the results are not readily transferable from lens to lens, let alone among different models, designs or makers. Cine primes, with a price point an order of magnitude higher, and with production budgets to match, could come with a full bokeh spec sheet, if anyone cared enough.

Struan Gray
5-Apr-2012, 01:28
Digital processing is full of traps for those who groove on optical character. Sharpening algorithms parse image data, hunting for things to construe as edges. Discrimination criteria based on difference thresholds result in selective and spatially discontinuous amplification of pixel value differences.


My PhD and subsequent research career were in probe microscopy. I have spent a lot of time worrying about being fooled by imaging artefacts, and teaching baby physicists why digital filters used blind will bite them badly, if only by hiding surprises and preventing serendipitous discovery. I am consistently surprised by how the general digital photography public will lap up what looks to me like an ugly digital slop, and call it excellent.

I didn't like Velvia either :-)

Struan Gray
5-Apr-2012, 01:36
We are left in the end pretty much where we started, at least until that bokescheissemeter (or whatever it was) becomes reality. We try lenses that others like or that made pictures we admire. If they please us, we keep using them. If not, they go back on the block. We are back to the journey, in which we might learn as much about the effect we want as we learn about lenses that produce them. The image is a superimposed stack of fuzzy spots, and figuring out how they will add up is probably most practically an empirical exercise.

If you have a lens to hand, there are some simple tests you can do to characterise the bokeh well enough for useful work. Sets of point lights at characteristic distances (stars, an LED net, dots on a flat panel computer screen) in and out of focus. Six to nine images will tell you if there are any ugly surprises waiting in the wings.

A craftsman's feel acquired through just using the lenses will often work just as well.

The problem comes when considering buying a new lens, or trying to help others struggling with their equipment choices. Great is the temptation to do good :-)

peter ramm
5-Apr-2012, 08:15
My PhD and subsequent research career were in probe microscopy. I have spent a lot of time worrying about being fooled by imaging artefacts, and teaching baby physicists why digital filters used blind will bite them badly, if only by hiding surprises and preventing serendipitous discovery. I am consistently surprised by how the general digital photography public will lap up what looks to me like an ugly digital slop, and call it excellent.

I didn't like Velvia either :-)
I think there is a naive inclination to trust image processing as an "enhancement" process. When I say naive, I mean just that. Most people are inexperienced with the fundamentals of image processing and why should they be? It is specialized material and it takes some study to understand. Even then, "understanding" means that one recognizes how little one really knows. How much does the LF photographer need to know about imaging science?

The scientist works from hypotheses, the craftsman works from knowledge. In the first lecture of an upper year course I would tell the students "Everything I am about to teach you is wrong, but it is the best guess we have". I just did it because I was evil and knew it would drive the med students crazy. Today I would be more gentle and appreciate that, in an applied field (like medicine or photography), people want data they can use without being concerned about the epistemology of their beliefs. Bokeh is an intuitive thing.

I have no problem with defining something by how it appears (as opposed to what it is). I just keep the two understandings distinct. Many photographers (sadly, not I) have a deep intuitive understanding of things like bokeh and exposure, and my informal side enjoys seeing the results of that sort of thought process. I respect a masterful initial acquisition in context. Photography is not a science. It is a craft.

Here I engage rant mode. So often I see photographers trying to define what they do in engineering terms. One only needs to follow the endless discussions of dynamic range on LULA, for example, to see that a formal definition of even basic imaging concepts is foreign to most photographers. There is the rare individual who combines formal and intuitive understandings of photographic imaging, but most LF photographers can simply avoid the naughty bits. I think the aesthetic of LF dictates that the best results come from trusting your eye and not worrying a whole lot about what is really going on. Does sharpening add artefacts or make the image better? Is bokeh distortion or enhancement? Well, both really.

Dan Fromm
5-Apr-2012, 08:50
Hmm. I have too many lenses, ought to dispose of some of them.

From time to time innocents post requests for advice about which lens to get. "I want a lens with a lot of bokeh. Which lens should I get?"

These are implicit want-to-buy listings. I'd like to know how to match my surplus lenses to the requests, short of just making things up.

jp
5-Apr-2012, 09:08
Hmm. I have too many lenses, ought to dispose of some of them.

From time to time innocents post requests for advice about which lens to get. "I want a lens with a lot of bokeh. Which lens should I get?"

These are implicit want-to-buy listings. I'd like to know how to match my surplus lenses to the requests, short of just making things up.

A photo is worth a thousand words. Roman (I think) sold his sigmar on here with a couple nice portraits in the ad. It's a very uncommon lens people can't do much research / image browsing on. People like obscure stuff. Show some photos take with it to show what it can do. Perhaps in the process, you'll grow to like it and not sell it.

Brian C. Miller
5-Apr-2012, 10:42
... Is bokeh distortion or enhancement? Well, both really.

The scientist works from knowledge, and seeks to explore the unknown. There was an interview recently with the astronomer who got Cameron to put the correct sky in the Titanic's sinking scene. He says that scientists are always puzzled by something, and are working on some new problem.

The craftsman works from knowledge, and seeks to make the unmade, to give physical form to an idea. Here, we make photographs, with big cameras. We paint with light, and according to Ambrose Bierce, rather poorly at that. Light, our paint, is spilled on the film, our canvas, in a fraction of a second. Very rarely do we actually paint, to deliberately color the canvas. Quite a few frown on it.

Both the scientist and the craftsman need to know their tools. The poor craftsman blames his tools, and doesn't take care of them. The good craftsman takes care of his tools, knows what they do, and uses them well. A lens' blur has at least five characteristics, and all of those are affected by at least two other factors. These characteristics can be analyzed, just like we analyze film for the Zone system. It just takes some photographs being made with repeatable test targets derived from a specification to create data that others can use to predict what will happen for them.

And then distortion can be used to enhance the final photographic image.

-- Brian "yes I'm working on it" Miller

E. von Hoegh
5-Apr-2012, 10:49
The scientist works from knowledge, and seeks to explore the unknown. There was an interview recently with the astronomer who got Cameron to put the correct sky in the Titanic's sinking scene. He says that scientists are always puzzled by something, and are working on some new problem.

The craftsman works from knowledge, and seeks to make the unmade, to give physical form to an idea. Here, we make photographs, with big cameras. We paint with light, and according to Abrose Bierce, rather poorly at that. Light, our paint, is spilled on the film, our canvas, in a fraction of a second. Very rarely do we actually paint, to deliberately color the canvas. Quite a few frown on it.

Both the scientist and the craftsman need to know their tools. The poor craftsman blames his tools, and doesn't take care of them. The good craftsman takes care of his tools, knows what they do, and uses them well. A lens' blur has at least five characteristics, and all of those are affected by at least two other factors. These characteristics can be analyzed, just like we analyze film for the Zone system. It just takes some photographs being made with repeatable test targets derived from a specification to create data that others can use to predict what will happen for them.

And then distortion can be used to enhance the find photographic image.

-- Brian "yes I'm working on it" Miller

Well said.

Photograph, n A picture painted by the sun without instruction in art. It is a little better than the work of an Apache, but not quite so good as that of a Cheyenne.

Ambrose had perhaps been irritated by listening to one too many fauxtographers discussing the late 19th century equivalents of "giclee prints" and "bokeh". (winking smiley)

rdenney
5-Apr-2012, 11:25
...fauxtographers...

What's that?

Rick "is that your tail I'm stepping on?" Denney

E. von Hoegh
5-Apr-2012, 13:48
What's that?

Rick "is that your tail I'm stepping on?" Denney

A neologism.

jp
5-Apr-2012, 13:57
What's that?


Yeh... One of those people who aren't on Apug.

Who use contemporary technology to make sometimes excellent photos and don't consider it inferior to analog.

E. von Hoegh
5-Apr-2012, 14:03
Yeh... One of those people who aren't on Apug.

Who use contemporary technology to make sometimes excellent photos and don't consider it inferior to analog.

Not quite, at least in my lexicon. A fauxtographer is someone who thinks buying expensive equipment and learning some jargon makes them a photographer.

Digital, analog, macht nichts as long as it's a good image.

jp
5-Apr-2012, 14:06
Not quite, at least in my lexicon. A fauxtographer is someone who thinks buying expensive equipment and learning some jargon makes them a photographer.

Digital, analog, machs nichts as long as it's a good image.

I completely agree, but the term is also used and abused on traditional photography sites to refer to practitioners of digital photography as if it's fake photography.

E. von Hoegh
5-Apr-2012, 14:09
I completely agree, but the term is also used and abused on traditional photography sites to refer to practitioners of digital photography as if it's fake photography.

I know, frankly I'm tired of the digital analog which is best debate, like the vinyl/CD debate. Of course, there is the derogatory term "digitographer" used to describe pixel counters.

Edit - Yeah, some of the attitude at some of those "traditional" sites is a bit much.

Dan Fromm
5-Apr-2012, 14:29
Digital, analog, machs nichts as long as it's a good image.

E., in the depths of your great old age you're losing your German. Macht nichts.

E. von Hoegh
5-Apr-2012, 14:32
E., in the depths of your great old age you're losing your German. Macht nichts.

You're right- thanks. And the verfluchte "s" isn't even next to the "t" on the keyboard. Fixed.

paulr
5-Apr-2012, 14:37
Paul, when people here start spouting gratuitous smears of contemporary photographic art, you're at pains to explain why they should keep an open mind and consider history, context and purpose to try to understand what they're seeing. You keep hammering at that despite endless provocation. More power to you! But here, where we have a technical term of craft which also has a history, context and purpose, you're out waving the pitchfork. What gives?

Aren't I allowed to have a loud, inconsequential opinion or two?

We might also need an emoticon for tongue-firmly-planted-in-cheek.
Yes, the word bugs. Yes, I'm over it.

Oren Grad
5-Apr-2012, 14:58
Aren't I allowed to have a loud, inconsequential opinion or two?

< putting wet noodles away >

Permission granted.

But no more than two, so please choose carefully.

< emoticon for tongue-firmly-planted-in-cheek >

paulr
5-Apr-2012, 15:00
I haven't seen the latest and greatest. My only caveat would be that eliminating LoCa after the fact requires making assumptions about what is the subject of the photograph and what is the 'best' way to present that subject in a photograph. I often find myself disagreeing with those choices, or shooting subjects which subvert them (such as early spring brambles, which at their peak have both the standard colours of LoCa in combinations which get ruined by automatic eliminators).

I'd be curious about your impressions. It's new to me; I just started playing with Nikon's raw processor. From the way it works I believe it's a kind of deconvolution algorhithm ... in other words, it doesn't make assumptions about the detail in the image, but rather about the nature of the degradation (which it then attempts to reverse).

In the couple of images I've played with, it's worked like magic. Specific kinds of fringes disappear, and there's no evidence of any processing in the places they were.

The lateral chromatic aberration tool works by a different method. In the Nikon version there's no adjustment. you just click it on, and the software analyzes misalignment of the color channels and works its magic. I'll have more to say about it after I've played more.

I've read that the DXO software handles lens aberrations even more magically, but have yet to get my hands on it.

I don't know for sure, but it's starting to seem like this kind of software is influencing choices made by lens designers. If they don't have to worry about simple distortions and lateral color anymore, they can concentrate on other qualities that are more crucial to get right before processing.

Oren Grad
5-Apr-2012, 15:13
I don't know for sure, but it's starting to seem like this kind of software is influencing choices made by lens designers. If they don't have to worry about simple distortions and lateral color anymore, they can concentrate on other qualities that are more crucial to get right before processing.

This is exactly right. Designers of lenses for some high-end small-sensor compacts (e.g., Panasonic LX5) and mirrorless cameras (many Four Thirds lenses) are candid about the fact that they are intentionally leaving in some attributes traditionally considered image defects - notably very substantial linear distortion - and then correcting for them in the manufacturer-supplied raw converter. The corrections are increasingly being picked up by the mainstream converters like ACR as well.

I don't yet know of any cases where this has been done deliberately with an SLR lens. But there's still a cost tradeoff, and I think part of what you pay so much extra for with the latest M-Leica lenses is the attempt to suppress certain aberrations as far as possible within the lens design.

uphereinmytree
7-May-2012, 10:54
will a studio shutters blades make my 8.75 inch verito less smooth compared to a perfectly round aperture? will it change the character perceptively

Mark Sawyer
8-May-2012, 14:15
will a studio shutters blades make my 8.75 inch verito less smooth compared to a perfectly round aperture? will it change the character perceptively

In practice, I would say in most cases, no. The only difference you would see would be if there was an echo of the aperture shape from a small highlight reflecting inside the lens.

But some very knowledgeable others would likely disagree with me...

Drew Wiley
8-May-2012, 14:35
Anyway, back to "bokeh" or whatever ... My Apo Nikkors have wonderful multiple aperture
blades, but otherwise not slow lenses, with a reputation for hard-sharpness. But given a
very long focal length the depth of field might be acceptably shallow. Since I already have
these on Sinar boards, guess I should just look thru them to get an idea ... then I'd just
need a Sinar shutter. They also have filter slots and cute little filter holders that something could be slipped into to mess up the clarity. Anyone ever try any of these for broke-eh or however you pronounce it?

Drew Wiley
8-May-2012, 15:17
Oh ... and for you folks squealing your protest over the term, Fauxtography ... I think I coined that. It has nothing to do with choice of tools or technique, which are basically
neutral by themselves. But it is intended as a deliberate slur to those who behave like
pimps toward natural subject matter, and slather it with supersaturated fake digital color just because they've never learned to actually look at things. I pity clowns like Peter Lik
or the late painter Kincaide. Never lived, never looked, never seen real beauty. What a waste.