Macro versus Process Lenses ?

[Ken Lee]

We know that Process lenses were made for process cameras, not LF cameras. We know that Macro lenses for LF are mounted in shutter, have more elements, and open wider than Process lenses. The diaphragms are different, because of whatever the shutter provides versus whatever barrel-lenses give - which is usually more blades. Coverage may differ also.

However, sweeping all of that aside, is there a qualitative difference in resolution or image quality ? In other words, if we shoot close to 1:1, and stop both lenses down to say f/16, will we see much of a difference in image quality ?

[Bob Salomon]

Of two dimensional or three dimensional objects?

[Ken Lee]

Thanks Bob: 3-dimensional subjects. Pumpkins, tulips, dishes, etc.

I hadn't considered that :)

[Bob Salomon]

Then a macro lens will easily outperform a process lens, especially away from the center of the format.

And process lenses, 600mm or shorter, were designed to be only used at f22 for their optimal results. A macro lens will perfom optimally over a range of aperture to f22, including f16.

Also, if preserving the shape of the originals a long macro lens like a 300mm is required to reduce foreshortening.

[Oren Grad]

Then a macro lens will easily outperform a process lens

In what ways?

[Mark Sawyer]

Bob, could you please expound a bit about how a process lens would have less performance with three-dimensional objects? I would think the depth of field would be similar at identical f/stops.

Also, weren't process lenses designed to take a variety of aperture shapes and sizes, hence the Apo-Ronars that close to f/260 and has a slot for Waterhouse stops?

I'm quite curious, as I've always used prcess lenses for my close-up work with very good results.

[Mark Sawyer]

Incidentally, here's my understanding of the differences between "general-purpose/macro/process" lens types:

A "general purpose" lens is optimized for use from infinity to near 1:1 at the film plane, and is well-corrected for all aberrations.

A "macro" lens is optimized for use at 1:1 and greater magnifications, and is well-corrected for all aberrations.

A "copy/process/graphic arts" lens is optimized for "close distances" (usually about 4:1 to 1:4), and is especially well-corrected for geometrically-distorting aberrations such as pin-cushion and barrel distortion so that "artwork" is not distorted when rephotographed for the printed page. Special attention is paid to making them as apochromatic as possible, though in modern lenses, all are apochromatic for nearly all practical purposes. Keeping the lens to these specifications usually means a smaller maximum aperture.

And I believe (someone correct me if I'm wrong) that eliminating focus shift is also a prime concern in making process lenses.

Any other differences I don't know of that someone can chime in on?
__________________

[Bob Salomon]

Bob, could you please expound a bit about how a process lens would have less performance with three-dimensional objects? I would think the depth of field would be similar at identical f/stops.

Also, weren't process lenses designed to take a variety of aperture shapes and sizes, hence the Apo-Ronars that close to f/260 and has a slot for Waterhouse stops?

I'm quite curious, as I've always used prcess lenses for my close-up work with very good results.

I can quote from specific examples. The May Company set up a super studio in St Louis for their catalog photography. After extensive testing with process lenses and macro lenses (all matched for performance at the factory in Germany) they found that best results were delivered by macro lenses when using 3-dimensional objects and the the results were simply more pleasing for reproduction in a catalog, where they were offering products for sale. Especially better were the reproduction of delicate, detailed items, like jewelry, at the edges and corners when the subject was not confined to the center of the field. It was not a matter of depth of field, it was how the subject was reproduced.

We had a similar situation with Dixie Cups studio in PA where they had to reproduce the cups and plates that they produced for various companies like MacDonalds and needed the most realistic reproduction and detail at 1:1 of the product for record shots.

BTW, macro lenses, like the Rodenstock Macro Sironar (discontinued) Apo Macro Sironar and Apo Macro Digital Sironars are not optimized for 1:1. They are optimized for a range of reproductio. The Macro Sironar was corrrected for 1:3 to 3:1 (depending on the orientation of the elements). The current macro lenses are corrected for 1:5 to 2:1 without changing the orientation of the elements.

A general purpose lens like the Apo Sironar S is corrected for 1:10 giving a working range of 1:5 to infinity. The Apo Sironar N, and similar lenses from other manufacturers, is corrected for 1:20 for ratios from 1:10 to infinity.

Neither type is corrected for "near 1:1".

[Peter K]

Every lens shows only a two-dimensional plane with optimum performance - depth of field is only an optical illusion - so there is no difference between two-dimensional and three-dimensional subjects for a certain image scale the lens is made for.

Macro-lenses have compared to process-lenses a bigger angle of view and a larger aperture, so more lenses are needed to get, more or less, the same performance as with a process-lens f/9.

The apochromatic correction used with process-lenses is needed to get the same image-dimension also with blue, green and red filtered images but it helps also to get more saturated colors without filters.

The small f-stops like f/264 and also the different aperture shapes are used to influence the shape of the typographical point by diffraction.

Peter

BTW to show a pumpkin at 1:1 one needs at least ULF. :D

[Dan Fromm]

Mark, not all of y'r definitions are generally accepted.

General purpose lenses are usually made to be used at magnifications of 1:10 and lower. In my book, 1:10 isn't very near to 1:1.

Macro lenses are made to be used in the range 1:1 to sometwhat lower often 1:10, when mounted normally. But there are macro lenses made to be used over a considerable range, e.g., the 100/6.3 Luminar; per Zeiss' propaganda it should be used from 1:8 to 8:1.

That said, there's no consistently-applied naming convention that's applied to lenses made for close-up photograph (1:1 to 1:10) and photomacrography (1:1 and higher). Each maker has his own way ...

Many process lenses are symmetrical (front cell identical to rear), so are best at 1:1 by construction. Some types, e.g., dialytes hold their corrections very all at low magnifications. At one time Rodenstock's propaganda asserted that Apo Ronars were better at infinity than telephoto lenses. This isn't true of modern teles.

But and however, there are some asymmetrical process lenses, e.g., TTH Apotals and "Copying Lenses," which are f/9 tessar types. Mine are very good at all distances. From which I conclude that reasoning from theory is nice but measurement is necessary too.

Ken, to address what I think you really want to know, in my lens trials macro lenses made for use around 1:1 were better than anything else at that magnification. The only exception I found was an enlarging lens, the 4"/5.6 Enlarging Pro Raptar. It came out roughly equal to a known good 100/6.3 Luminar from 1:4 to 4:1, both lenses wide open. Stopping down made them worse. If nothing else, process lenses are handicapped by their small maximum apertures. I've tried only one process lens seriously around 1:1, a 55/8 Repro Claron, and the comparable real macro lenses I tried were visibly better.

I haven't had the chance to play with Rodenstock's, Nikon's, or Leica's 100 mm +/- macro lenses so can't comment. I do know that shorter Macro Nikkors are better than the equivalent Luminar.

I also think that agonizing about image quality in the plane of best focus when shooting around 1:1 is silly. Regardless of the lens used here's not enough, and there isn't enough depth of field either.

Cheers,

Dan

[Dan Fromm]

Ken, I just realized that I slightly reread y'r question. At f/16 set at 1:1 the effective aperture is f/32 and all lenses are on the edge of poor, as in will make negatives that can't be enlarged much more than 6x.

[mdm]

I am far from an expert, however I do mostly closeups and I have a multicoated 240mm APO Ronar and a wonderful 135mm Sironar S. In my opinion the Ronar gives outstanding 3 dimentional results, contrasty and almost sculptural, like chiseled basalt. In my opinion it is much sharper than the Sironar S, although because it has a longer focal length it is usually less out of its comfort range at max extension. I love the tones from the Sironar S and it has a glow about it. It is a very fine lens and I am privelaged to own one, specially in the 135mm focal length. There is a 120mm macro sironar for sale somewhere near me and I too have been wondering if it is worth forking out the cash to buy a macro sironar. I have concluded that while it would probably be an improvement on my 135mm sironar s it would be less of an all rounder and will therefore not be worth the cash. If I had a 150mm sironar s then the macro would be the way to go. If you want to know where it is, Ken, pm me and I will spill the beans but you could probably get one cheaper nearer to you.

David

[Bruce Watson]

I've got questions about this too, so I'm reading this thread to learn more.

When I last investigated this topic (about five or six years ago IIRC) someone said that "normal" lenses preformed fairly well down to about 1:2. As in you wouldn't much notice the difference between a "normal" lens and a macro lens there. As your magnification ration increases from there, macro lenses begin to shine more and more, up to around 4:1. And if you want more than 4:1, get a microscope! (I believe that was said in more or less jest).

Since I didn't need 1:1, and seldom ever go to even 1:2, I let the matter drop. I didn't really want to buy yet another lens at the time.

So what I want to know is what Ken wants to know -- what are the qualitative, visual improvements that a macro lens brings to the party? Said another way perhaps: what aberrations in a normal lens get aggravated by close work?

[Ken Lee]

"At f/16 set at 1:1 the effective aperture is f/32 and all lenses are on the edge of poor"

At 1:1 we give 4x the exposure time due to "bellows extension", but it never occurred to me that the focal length actually doubles, f/16 becomes effective f/32, and we reach the diffraction limit.

I mention f/16 because I have been shooting in that vicinity, to get some - but not a lot (http://www.kenleegallery.com/images/forum/img015.jpg) - depth of field. That photo was made with a 240mm APO Nikkor, at f/16, on 5x7 HP5+. It's around 1:1, give or take a fraction - although I haven't measured.

I have nothing but respect for Bob's experience and advice.

Given that I shoot 4x5 and 5x7, scan on an Epson 4990, and rarely enlarge more than 3-4x, I wonder whether I would see the kind of difference to which Bob refers.

[Peter K]

At 1:1 we give 4x the exposure time due to "bellows extension", but it never occurred to me that the focal length actually doubles, f/16 becomes effective f/32, and we reach the diffraction limit.
Of course it's not the focal-lenght but the effective f-number that doubles.

Also the diffraction limit depends not on the effective f-number but on the mechanical diameter of the diaphragm and the wavelenght of light in use, lets say 550nm. So with a long focal-lenght the diffraction limit is reached with a much smaller f-stop compared with a short focal-lenght.

Peter

[Peter K]

So what I want to know is what Ken wants to know -- what are the qualitative, visual improvements that a macro lens brings to the party? Said another way perhaps: what aberrations in a normal lens get aggravated by close work?
You will not see much difference in the center but off-axis image points will reproduces as unsymmetrical patches by coma and astigmatism. Depending on the lens construction also the curvature of field will increase together with distortion. The result is a blurred image.

Peter

[fuegocito]

I am curious about this topic as well, and as to the claim one performs better, is it possible to see some examples... I am intensely intrigued by the idea of how a three dimensional object can be better rendered/represented/reproduced by a particular optical design. I think this is definitely one of those case a picture is worth a thousand words:)

[Dan Fromm]

Of course it's not the focal-lenght but the effective f-number that doubles.

Also the diffraction limit depends not on the effective f-number but on the mechanical diameter of the diaphragm and the wavelenght of light in use, lets say 550nm. So with a long focal-lenght the diffraction limit is reached with a much smaller f-stop compared with a short focal-lenght.

PeterPeter, please give a reference.

[Peter K]

Also with a single lens like a meniscus from an eye-glass and a strong filter one can get a "sharp" image in the center of the image. Such a lens is a "monochromate" with a narrow angle of view. To increase the angle of view one has to correct the lens faults specially at the outer areas by combining lenses. If the whole image area shows even "sharpness" for the focussing plane also other planes in front and behind the focussing plane will show more details too. So a three dimensional object will be better rendered. Specially if the details are smaller as the eye can resolve at the final image.

[Peter K]

Peter, please give a reference.
http://en.wikipedia.org/wiki/Fraunhofer_diffraction

Have fun

Peter

[Nathan Potter]

I, likewise, have wondered about the visual differences between a process lens and a macro lens and have kinda thought that any difference may not be sufficient to cause worry. I have assumed that a process lens was designed and optimized for the copy of flat objects, thus optimized for flatness of field at a maximally large aperture so as to achieve highest resolution by minimizing diffraction. But darned if I can think of why one might yield images manifestly different from the other at a given FL and working aperture.

Nate Potter, Austin TX.

[Ken Lee]

Following the mathematics is fairly trivial. We all appreciate the clever inside joke at this point:

"The above integral can then be approximated as..."

... No, just kidding. I bow before all Physicists.

[Ken Lee]

At 1:1, we often use a lens at double its infinity extension. For example, on 4x5, a 150mm lens, or on 5x7, a 210mm lens.

Since the circle of coverage doubles in diameter, are we not likely, in such cases, to use mainly the center of the circle of coverage ?

If that is true, then it seems that what the Macro lenses offer, is extensive use of View Camera movements at close range - with confidence that even out towards the extremes of coverage, the image will be free aberrations like coma, astigmatism, etc. (As Peter explained.)

That makes sense, because they are View Camera lenses, not just Large Format lenses or Process Camera lenses. Just as modern designs improve over vintage designs - by offering greater usable image circles at high fidelity and correction - these Macro lenses do the same.

Is that a fair assessment ?

[Peter K]

It is a fair assessment.

But this lenses are not realy macro-lenses, simple microsope lenses, like the Luminar, Summar etc. but "close-up lenses".

Peter

[Mark Sawyer]

At 1:1, we often use a lens at double its infinity extension. For example, on 4x5, a 150mm lens, or on 5x7, a 210mm lens.

Since the circle of coverage doubles in diameter, are we not likely, in such cases, to use mainly the center of the circle of coverage ?



Remember that macro lenses often don't cover at infinity, so depending on the extension, you may still be using most or all of the coverage.

[Dan Fromm]

Um, Peter, back when I was chasing macro lenses I tried some shots at distance with a 100/6.3 Neupolar. It covered 6x6 +/- a little and was very sharp. Not what I expected. I mentioned this to Charlie Barringer, who told me in return that he'd shot his 100/6.3 Luminar at distance on a Contax Aria and that it was not too bad either.

Macro lenses such as the Luminar are typically better corrected and have better field flatness than simple microscope lenses. Although, come to think of it, I have a little Beck (UK) 5x objective in the drawer that does quite well on 35 mm at around 10:1.

Cheers,

Dan

[Peter K]

Macro lenses such as the Luminar are typically better corrected and have better field flatness than simple microscope lenses.
Dan, the Luminar is a simple microscope lens. Because it cannot used with an eye-piece or photo eyepiece as a compound microscope.

Peter

[mdm]

It appears to me, looking at the data on Ronars, Sironar S's and Macro Sironars, that the primary difference is in working apperature. The process lenses have a working apperture of f22, the Sironar S's f11-22, and the Macro Sironars f8-11. Coverage does not seem to be an issue with any of them.

So it seems that a macro lens is corrected at a faster working apperture. If you are stopping down to f22 or smaller for the dof (aka Kens razor sharp flowers) it is irrelevant which you use, a process lens is the rational option. If you want to use a narrow depth of field to best advantage then a macro lens is the way to go.

David

[mdm]

So perhaps by using a shorter macro lens one can have ones cake and eat it too.

David

[Ken Lee]

One other consideration is what we might call... Quality.

I'm unable to find these for Fujinon or Nikkon - perhaps they exist somewhere in Japanese - but the MTF curves for the Rodenstock and Schneider Macro lenses, are impressive.

http://www.rodenstock-photo.com/mediabase/original/e_Rodenstock_Analog_Lenses_27-42__8226.pdf

http://www.schneideroptics.com/pdfs/photo/datasheets/macro-symmar/macro-symmar_56_120_2.pdf

[mdm]

First attachment made with a 240mm Ronar, second made with a 135mm Sironar S. Unfortunately I do not own a macro sironar to use in the comparison. They both look good to me, the Ronar may have higher resolution, I can't think of a more three dimensional subject. Both shot at f16 at either 1/8th or 1/15th of a second. Same camera position. Outdoors so movement could be a factor but I shot a holder for each lens and have used the best exposure. Equal but minimal sharpening applied on resize to both. I dont see any reason to get a macro lens because I would be surprised if it could make much of an improvement on either. The jpegs really do not do justice to the original files but I don't have time to put up a crop.

David

http://www.flickr.com/photos/45190700@N06/4459057036/
http://www.flickr.com/photos/45190700@N06/4459057036/

[Bob Salomon]

First attachment made with a 240mm Ronar, second made with a 135mm Sironar S. Unfortunately I do not own a macro sironar to use in the comparison. They both look good to me, the Ronar may have higher resolution, I can't think of a more three dimensional subject. Both shot at f16 at either 1/8th or 1/15th of a second. Same camera position. Outdoors so movement could be a factor but I shot a holder for each lens and have used the best exposure. Equal but minimal sharpening applied on resize to both. I dont see any reason to get a macro lens because I would be surprised if it could make much of an improvement on either. The jpegs really do not do justice to the original files but I don't have time to put up a crop.

David

One major difference between a macro lens and the lenses that you used is detail in the corners as well as the edges. Your shots only illustrate a subject in the center. In addition the Apo Ronar performs optimally at f22 only, not f16. And since neither is done with a macro lens you have not compared the results to a macro. Only a process lens to a lens corrected for 1:10.

[mdm]

That is true. However my Ronar is tack sharp wide open, I do not doubt that it performs to specifcation at f22. Perhaps it is vulnerable to minor distortion away from f22, I do not know because I am not reproducing maps. I would love to have a 120mm macro sironar but first I must do justice to what I already have.

It is probably true that a macro sironar renders a small scene in a more pleasing way than a sironar s, the ronar and the sironar s render a scene very differently, a heliar or a tessar would differ again. Probably, the difference would show most for a colour photograph, and if I made my living photographing precious jewls with subtle colours and shiny metals, and I needed to catch the eye of the most discriminating readers of glossy catalouges, I would have a macro sironar. I am just an overworked dairy farmer and I use a camera to escape for an hour or two, here and there, which is all the time I can afford.

David

[mdm]

Having made some A3+ prints now, it is clear (from a very unscientific comparison) that the Ronar produced a nicer result overall than the Sironar S. This is a multicoated Ronar in shutter. Not surprising really, considering that it was operating closer to its comfort range than the Sironar S was. I believe that a Macro Sironar would have done a better job again because it would have been doing exactly what it was designed for. How much better?

Close to 1:1 a multi coated process lens is clearly better than a normal lens, even a very good normal lens. I will be using the Ronar for my flowers from now on and putting the Sironar S onto a field camera where it belongs. Those 240mm Ronars floating around for very little are the bargain of the century.

It is very hard to take a good picture of a dandelion, try again David.

[Ken Lee]

http://www.kenleegallery.com/images/forum/img050a.jpg
Daffodils, March 2010
Sinar P, 210mm Macro Sinaron DB
5x7 HP5+, Pyrocat HD

[mdm]

That is beautiful. The fringes of the inner bells certainly are wonderfully dimensional. I can't tell from here that this one is any better than your other flowers made with other lens's. Do you have an opinion yet, Ken?

David

[mdm]

Here is a f9 process lens shot wide open, wider than f9, on fp4+ developed in pyrocat, 8min in BTZS tubes I think.

Second one was with a Sironar S, also wide open and fp4+ in pyrocat but may have been 36 minutes with 4 agitation cycles in 1:1:150, not shure though.

There is a lot of vey fine detail in both of theese although it is not easily aparent in the jpegs. I still have not seen anything that can justify spending $$$ on a macro lens.

[Ken Lee]

That is beautiful. The fringes of the inner bells certainly are wonderfully dimensional. I can't tell from here that this one is any better than your other flowers made with other lens's. Do you have an opinion yet, Ken?

David


My objective opinion: I will make the same image with 2 or more different lenses. I have a 240 APO Nikkor, and a 240 Fujinon. We'll see what the difference is on film.

My subjective opinion: Bob Salomon has tirelessly and patiently pointed out that Macro lenses are designed differently from Process lenses, that manufacturers have taken the time and made the effort for genuine and tangible reasons. As soon as I looked through the ground glass, I could see a difference in overall image fidelity: clarity, sharpness, and color. Black and white doesn't tell the whole story.

Some of this may be due to the lens opening to f/5.6 instead of f/9, but it strikes me as more than that. The lens gives a certain look that I get from my Rodenstock APO-Sironar S 150 at normal distances. It's hard to describe, other than that it looks alive - like what we see with the naked eye.

Here's another one with the same lens, film, etc.


http://www.kenleegallery.com/images/forum/img063.png