Highest Sharpness & Resolution

[Mirumir]

Is there, among RODENSTOCK, SCHNEIDER, NIKON and FUJINON lenses for 4x5"
camera, the one (probably 150 - 180 mm focal length), wich can deliver HIGHEST POSSIBLE resolution and sharpness in every microdetail, not only in the center of the image, but on the whole 4x5" film sheet, from corner to corner?
Thanks much for help.

[chilihead]

Fujinon A 180mm f9

[paulr]

no. they're all sharper in the middle than at the edges. they're all sharpest at one aperture, and at one magnification. some are a bit sharper than others at their peak settings, some are more consistently sharp over a range of settings.

most reasonably modern lenses are so sharp that you'll have a hard time telling the difference in real life. issues like depth of field and wind and vibration and focus error will more than make up for any difference in lens sharpness most of the time. every once in a while when things are close to perfect you'll get a chance to see how good your lens really is.

[Bruce Watson]

no. they're all sharper in the middle than at the edges. they're all sharpest at one aperture, and at one magnification. some are a bit sharper than others at their peak settings, some are more consistently sharp over a range of settings.

most reasonably modern lenses are so sharp that you'll have a hard time telling the difference in real life. issues like depth of field and wind and vibration and focus error will more than make up for any difference in lens sharpness most of the time. every once in a while when things are close to perfect you'll get a chance to see how good your lens really is.

What Paul said. Lens design is compromise. Perfection is not possible. But with modern lens design and manufacturing techniques lenses are pretty darn good. And when conditions are just right, they can be scary good, as Paul says.

[Edwin Lachica]

What application would you be using the lens for?

[Bill_1856]

Q:
Is there...among lenses for 4x5"
camera, the one...wich can deliver HIGHEST POSSIBLE resolution and sharpness...?

A: Yes there is, and it's on my Technika right now.

[Jack Flesher]

The sharpest lenses I have seen that fully cover 4x5 and stayed sharp corner to corner in the 150 - 180 range are the Rodenstock APO S's and the Schneider APO L's.

As you go longer, surprisingly, one of the sharpest lenses I ever tested was a Schneider Kern 360 Gold-Dot Dagor. That lens covers 8x10 and stayed laser sharp to the corners...

Cheers,

[Brian Ellis]

No. Among other things, different lenses are optimized for different mag ratios, so while one lens might produce the "highest possible resolution and sharpness" at one ratio it wouldn't necessarily do so at another ratio. And even if one lens did produce the "highest possible resolution and sharpness" everywhere all the time, all the other things in the chain from the subject of the photograph to your output are so compromised, and the competing lenses are so good, that I don't think it would matter, at least not for any normal application. Better to buy any good modern lens of a given focal length and design from any of the major manufacturers and then worry about your tripod, your film holders, the alignment of the front and back standards on your camera, the focus point of your scanner or the alignment of your enlarger, etc. than to try to find the lens that produces the "highest possible resolution and sharpness" as measured on an optical bench.

[rob]

I bet the 180mm makro symmar or 210mm Nikkor am ed are super sharp corner-to-corner at 1:1.

[JPlomley]

Rob, cannot comment on the macro lenses you mention, but the 120 AM ED Nikkor is a solid performer.

Agree with Jack on the Sironar-S series. I started with the 135mm, loved it so much I added the 210 and 300mm. All stellar performers. 55mm APo Grandagon is extremely impressive as well, but the IC is a PITA.

[JPlomley]

Oops. Just read the question more carefully, so ignore my 55mm comment (or not).

[Ken Lee]

Is there, among RODENSTOCK, SCHNEIDER, NIKON and FUJINON lenses for 4x5" camera, the one...

When you get down to this level of comparison, it will be important to choose the best specimen from a set of otherwise "identical" lenses. There is probably some % of variation within lenses of the same line.

You might find it revealing that an old $60 lens - almost 100 years old - on a vintage 11x14 camera, will easily outperform the best modern lenses on 4x5. See Jim Galli's article here (http://tonopahpictures.0catch.com/Conley/1114Conley.html).

To quote Ken Rockwell (http://www.kenrockwell.com/tech/format.htm), discussing his affordable Tachihara camera: "This $300 used 4x5 is sharper than a new $3,000 Hasselblad and worlds beyond a $5,000 Leica or Contax."

[Gordon Moat]

Basically agreeing with Ken Lee on this; there is sample variation to consider. So you might get two seemingly identical lenses from one manufacturer, and find that one will outperform the other.

In theory, a Linhof or Sinar branded lens has been more thoroughly quality controlled and tested. So you might suppose that buying your lens through Sinar or Linhof would give you a better sample. The other side of this is that lenses branded Caltar are seconds, or not as good examples, basically bargain or discounted lenses. Calter lenses can often be Rodenstock lenses, and a few have been Schneider lenses; it should be possible to find a good example branded as a Caltar.

As you focus on an object/subject that is closer, you might find better performance on many lenses due to not being at the edge of coverage. This might be different than the same lens used with extreme movements, or at infinity distance. I have found that usually coverage is more important for what I want to accomplish, though my Nikkor-W 180mm f5.6 performs extremely well from a resolution viewpoint.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[paulr]

[I][COLOR="Blue"]You might find it revealing that an old $60 lens - almost 100 years old - on a vintage 11x14 camera, will easily outperform the best modern lenses on 4x5.

well, he was also comparing enlargements to contact prints, which is probably a bigger variable than the lenses, and almost as big a variable as the format difference.

I don't think you can conclude much at all about lenses from a comparison like that, except that contact prints from old lenses can look great (not really a news flash!)

[Ken Lee]

I don't think you can conclude much at all about lenses from a comparison like that

You're certainly right.

I confess: I find it amusing to see what happens when we drop the constraint on film size, and just face the broader question: "How to get the highest sharpness and resolution ?" It puts things in a different perspective - especially for those of us conditioned by our culture, to consider only "the latest" technology.

[paulr]

[I][COLOR="Blue"]I find it amusing to see what happens when we drop the constraint on film size, and just face the broader question: "How to get the highest sharpness and resolution ?"

it's amusing because it leads to the lunatics here:
http://www.gigapxl.org/technology.htm
;)

[Ole Tjugen]

The big question is: How much resolution do you need, and why?

http://www.bruraholo.no/images/Lodalen.html is an example of what can be done with an elderly lens not famous for sharpness (Angulon 165mm f:6.8) and outdated 5x7" colour film, at non-optimal aperture (f:32).

It's going to outperform any current DSLR anyway! :)

[Robert A. Zeichner]

Apparent sharpness is a product of both resolution and contrast. The two together are what defines the sharpness of a lens and one without the other leads to poor perfomance. This is one of the reasons why MTF (modulation transfer function) has been adopted as the measurement technique most meaningful in comparing sharpness of various lenses. MTF is explained in great detail on a number of sites and if you google MTF you will find lots of stuff to study, but in short, MTF is the measurement of dynamic range of brightness across incrementally higher and higher frequencies (pairs of alternating black and white lines of decreasing thickness). As you approach the limits of resolution, the dynamic range (contrast) diminishes to a point where picture detail is obscured. It's best to read up on this and look at some of the excellent illustrations depicting this.

That said, a number of factors prevent otherwise excellent lenses from performing to their fullest. Some of these are:

Vibration: often caused by inadequate tripods and faulty or inappropriate cable releases. (I don't know who should be credited for this quote, but "The sharpest lens is a tripod").

GG/Film Plane Misalignment: This is common in used LF cameras that have had their ground glass screens changed, replaced or modified by unknowledgeable tinkerers. If the film plane is displaced just a few thousandths of an inch, it can make a difference in the sharpness of your negatives. I've heard numerous stories about people trading this lens for that in search of the perfect one, only to find out later on that their ground glass was improperly shimmed.

Improper lens shading: This topic is being beaten to death on several other threads, but in short, many otherwise fine lenses exhibit a certain amount of veiling glare that robs the image of contrast. By effectively shading the lens to prevent as much non-image-forming light from entering it, contrast performance can be significantly improved and when you improve contrast, you improve apparent sharpness.

Crappy Filters: You put an uncoated piece of window glass in front of a $1500 lens and you invite image degradation.

I hope some of this is of value to you.

[Brian K]

I agree with many of Robert Zeichner's comments but he forgot to add a few:

Shutter vibration, the bigger the shutter the greater the affect of it's own vibration on sharpness at low shutter speeds.

Film flatness, whether using a RFB or a sheet film holder, film sags and buckles. Using an rfb that has excellent flatness makes a difference and taping sheet film or using a cut film holder with a pressure plate (i.e. Sinar) helps.

Human error, most often soft focus is the result of improperly seated holders or just poor focusing on the part of the photographer. Also with lighter weight cameras heavy film holders or RFBs can make the rear standard tilt out of position.

Wind, even with a sturdy tripod if you have bellows extension you basically have a sail, and even light breezes can shake the camera, an umbrella as a wind screen comes in very handy.

[paulr]

add to Robert's list what might be the biggest one of all: in most situations, much of the subject will be somewhere besides the plane of focus. "depth of field' is about image quality that's subjectively good enough; but anywhere away from the plane you're not going to see the lens at its sharpest.

[David A. Goldfarb]

And then even if you have a heavy camera support, you may have to think about ground vibrations at high magnifications or over long distances you may have to think about differences in air temperature refracting the light reflected from the subject.

[Mark Sawyer]

The other side of this is that lenses branded Caltar are seconds, or not as good examples, basically bargain or discounted lenses. Calter lenses can often be Rodenstock lenses, and a few have been Schneider lenses; it should be possible to find a good example branded as a Caltar.


My understanding is that the lenses are mounted in the already-engraved Caltar/Rodenstock housing before being tested, as alignment in the mounting is extremely important to lens performance. This would preclude any "seconds" being branded as one or the other, unless the lenses were remounted, which could change the lens' performance significantly..

Linhof and Sinar return any "unacceptable" lenses; I'd love to know what percentage they find "unacceptable". Anybody know? Or know what happens to the lenses they refuse? (Would Schneider-Kreuznach really rebrand such a lens as their own and release it?)

To all the other factors that influence resolution, I'd add developer choice and developing technique as very important to the ultimate resolution.

[Brian Ellis]

" . . . The other side of this is that lenses branded Caltar are seconds, or not as good examples, basically bargain or discounted lenses. Calter lenses can often be Rodenstock lenses, and a few have been Schneider lenses; it should be possible to find a good example branded as a Caltar. . . . "
Gordon Moat

I don't think that's correct. I remember reading an article about Caltar lenses in either View Camera or Photo Techniques by a guy who used to work for Calumet. IIRC there was no selection process based on quality that was responsible for determining which lenses ended up as Rodenstocks (or whatever) and which ended up as Caltars. Where did you hear that Caltars are seconds or not as good examples as those that end up as Rodenstocks?

[harrykauf]

uhm...troll?

[Gordon Moat]

Man I really enjoy when people selectively snip what I type. Once again, this is the proper quote:

In theory, a Linhof or Sinar branded lens has been more thoroughly quality controlled and tested. So you might suppose that buying your lens through Sinar or Linhof would give you a better sample. The other side of this is that lenses branded Caltar are seconds, or not as good examples, basically bargain or discounted lenses. Calter lenses can often be Rodenstock lenses, and a few have been Schneider lenses; it should be possible to find a good example branded as a Caltar.

Maybe my English usage is improper, but my understand is that one paragraph contains thoughts that are connected. So . . . the phrase In theory applies to that entire paragraph I typed. When someone quotes only part of the paragraph, it changes the meaning of what I typed.

Also, for the record, I own a Caltar lens. It happens to be one of my most used lenses, and is nearly the best one I use. Now if that's a troll, then I will accept that classification.

As one of my college professors use to state: RTFQ

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[harrykauf]

oh god, I am sorry. the troll remark was aimed at the original poster who has posted
one comment with the typical "whats best ever" question and doesnt really take part
in the discussion that follows.

[Gordon Moat]

Okay, Harry, kein problem. I agree, a what's best type of post, without much follow-up from the OP, might be considered a troll, or at the very least a misguided question.

[Mark Sawyer]

Man I really enjoy when people selectively snip what I type. Once again, this is the proper quote:

In theory, a Linhof or Sinar branded lens has been more thoroughly quality controlled and tested. So you might suppose that buying your lens through Sinar or Linhof would give you a better sample. The other side of this is that lenses branded Caltar are seconds, or not as good examples, basically bargain or discounted lenses. Calter lenses can often be Rodenstock lenses, and a few have been Schneider lenses; it should be possible to find a good example branded as a Caltar.

Maybe my English usage is improper, but my understand is that one paragraph contains thoughts that are connected. So . . . the phrase In theory applies to that entire paragraph I typed. When someone quotes only part of the paragraph, it changes the meaning of what I typed.

Also, for the record, I own a Caltar lens. It happens to be one of my most used lenses, and is nearly the best one I use. Now if that's a troll, then I will accept that classification.

As one of my college professors use to state: RTFQ

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

Being the first offending snipper, I'll apologize. I was going to the pertinent part of the information rather than having the reader go through three paragraphs. The original post was still there for anyone following the thread.

Regardless of whether it was given as fact or theory, it was (I think) faulty information, and a bit of a disservice to Calumet, Rodenstock, and anyone shopping for a good lens...

[Gordon Moat]

No worries Mark. Perhaps I could have stated the entire paragraph more eloquently at first. When one looks for used lenses, there are some that go for a premium, often Linhof or Sinar branded lenses, and other that go slightly below what name branded lenses run, usually Caltar, sometimes a few others. Then there are lenses with Schneideritis, though certainly Schneider lenses are not the only ones that exhibit such tendencies. The used prices seems to suggest that a Linhof or Sinar branded lens would be better than a normal Schneider or Rodenstock, and that a Caltar branded lens would be worse, hence the theory, though it is loosely based upon price and apparent perceptions on the market. Personally, I don't think it is true, which is why I stated: In theory . . . . .

However, the fact is that people so seem to pay more for Linhof and Sinar branded used lenses than similar Schneider and Rodenstock. People also tend to pay less for Calter branded lenses than Schneider or Rodenstock. Again I think this gets back to sample variations. Branding might promise some quality level, yet the fact remains that there are some quite good lenses available on the used market that are branded as Caltar. Due to sample variation, a Linhof or Sinar branded lens might actually perform to a lesser degree than a Rodenstock or Sinar, or even to a lesser degree than a Caltar branded lens. Those who shop carefully might find true gems out there, but it all depends upon whether one gets a good example, and not on the name on the lens.

I hope that is clearer. Also, Fujinon and Nikkor lenses are quite good, though still subject to sample variation. Depending upon focal length desired, they should be compared to any Schneider or Rodenstock.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[Mark Sawyer]

No worries here either, Gordon!

One thing I've often wondered about though, is that for all the disrespect shown the little Angulon 90mm f/6.8, it's perhaps the most common of the lenses Linhof chose to put it's seal-of-approval on... (I have a little 90mm Angulon, and think it's just great!)

[Dan Fromm]

Mark, the Linhof acceptance test procedure screens out the real clinkers. That's all.

It doesn't guarantee getting a good lens, it guarantees not getting a really bad one.

All of which is moot with used lenses, since they've all suffered more or less abuse and can't be counted on to be as good as they were when they left the factory. Some may be as good as new, none will be better ...

The original poster's question has something otherworldly about it. More resolution is better than less, I guess, but the only way to get really good resolution on film is to shoot at larger relative apertures than are normally used in LF photography. In addition to using a good lens, meticulous technique, as has been pointed out, is necessary and so is a high resolution emulsion. This ain't photography with any format as most practice it.

And the only way to get a really sharp large print is to start from a really sharp large negative. I mean, there are good reasons why 24x36 negatives don't yield sharp prints larger than 8x10.

harrykauf, I had the same evil thought about trolling as you when I read the original post in this thread. Its gratifying that the troller, if that's indeed what the OP was, has failed to other people to fight.

[Atul Mohidekar]

Going back to the original question...

I have heard that 110mm XL Super Symmar has extremely good sharpness. I have also heard 135mm APO Sironar S is extremely sharp lens, too. Anyone has compared these lenses in terms of sharpness or any other desirable characteristics?


// Atul

[Brian Ellis]

Man I really enjoy when people selectively snip what I type. Once again, this is the proper quote:

In theory, a Linhof or Sinar branded lens has been more thoroughly quality controlled and tested. So you might suppose that buying your lens through Sinar or Linhof would give you a better sample. The other side of this is that lenses branded Caltar are seconds, or not as good examples, basically bargain or discounted lenses. Calter lenses can often be Rodenstock lenses, and a few have been Schneider lenses; it should be possible to find a good example branded as a Caltar.

Maybe my English usage is improper, but my understand is that one paragraph contains thoughts that are connected. So . . . the phrase In theory applies to that entire paragraph I typed. When someone quotes only part of the paragraph, it changes the meaning of what I typed.

Also, for the record, I own a Caltar lens. It happens to be one of my most used lenses, and is nearly the best one I use. Now if that's a troll, then I will accept that classification.

As one of my college professors use to state: RTFQ

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[Brian Ellis]

I have no idea what you were saying if it wasn't that Caltars are seconds but my apologies if quoting only the second sentence changed the meaning of what you wrote.

[Ole Tjugen]

...
One thing I've often wondered about though, is that for all the disrespect shown the little Angulon 90mm f/6.8, it's perhaps the most common of the lenses Linhof chose to put it's seal-of-approval on... (I have a little 90mm Angulon, and think it's just great!)

The Angulon has one weakness: Only the outer elements are supported by the barrel; the two inner elements of each cell are only supported by the cement holding them to the outer element. Under adverse storage conditions (high temperature, vibrations, and standing "on end") these inner cells may creep off axis, which really buggers up the collimation.

All but one of mine are exellent (90, 120, 165, 210); but one (a 90) has dropped the inner elements of the front cell completely. But that's OK, since I bought it as a very cheap shutter. :)

I also make sure that if I'm not using them for any length of time, my Angulons are stored flat.

[Herb Cunningham]

Almost hate to clog up bandwidth , But-- If you go to galleries and look at what folks are actually selling, and then look at some old Karsh photo books, where he shot mostly 8x10 with a Kodak Commercial Ektar, 14 inch, why bother with the techies arguments.

If you are doing some kind of laboratory experiment, ok, get the 150 Super Symmar XL, which covers 8x10, and use the middle of it. The human eye won't be able to see the fine detail it can reproduce. And shoot at f11, which i beliebe is the max sharpness point.

Finally, Barry Thornton's Edge of Darkness did a sharpness test-result, a heavy tripod is the best lens!

[Maris Rusis]

The highest possible "resolution and sharpness" is an ideal that is difficult to realise even with the best designed, best made lenses. Inter-lens variability, even with lens batches that all pass specification, is a factor.

I recall in my previous career as a microscope salesman inspecting a batch of Zeiss 100x plan-opochromatic microscope objectives. These lenses are made practically without regard to cost or complexity to be the highest resolution sharpest visible light lenses possible. All perform to virtually 100% of what is theoretically possible and they cost multi-thousands each.

Imagine my surprise after look-testing them all that I got the impression that some were better than others. A colleague confirmed my choices. Informal tests of non-Zeiss lenses showed a similar thing.

The only way to get the highest resolution sharpest lens in the world is to pick batches from prestigious manufactures and test the units individually. As a seller of lenses this is a privilege I would be disinclined to grant to any buyer.

[Mirumir]

Dear friends!
First, let me thank you all, who has responded. True, I did not expect that much participation.
Sorry for not taking a part in this discussion immediately - I've got a limited Net access, from time to time, and not at home.
Some comments on the motivation to post this topic.
Earlier I used to shoot on 6x9 format, mainly b&w, developing the film in AGFA Rodinal, diluted 1:150, to get really sharp contours of the images' objects. Then, in order to keep up the resolution captured by the lens and the film, and not to loose a fraction of it during darkroom printing, my 6x9 enlarger has been modified to work with pin-point light source. The idea behind darkroom printing with pin-point light source, as you know, is that the light-emitting element of the lamp must be smaller than the working diaphragm (aperture) of the enlarging lens. In this case every microdot of the film has just ONE its exact shadow on the paper, so the whole projected image turns out to be absolutely non-degraded, in terms of sharpness. On the contrary, an ordinary condenser or dichroic enlarger, wich produces highly dispersed light, will NEVER be capable of printing an EXACT copy (from the potential sharpness point of view) of the negative to be enlarged, because in such a system every film micrograin casts down not a SINGLE, but SEVERAL its shadows, forming slightly blurred, not CLINICALLY exact enlarged copy of your negative.
So, trying to switch over to 4x5" format and planning to put potentially as much visual quality and harmony in the future work as I can (and as today's technology permits), there is a need to find a lens, capable of producing an even, high resolution picture (together with some other important optical characteristics).
On "...the tripod is the sharpest lens..." Of course, solid, rock-steady tripod is very important, but if your lens is not that good, there is just NO tripod to help.
Thank everybody for your comments and attention.
Be Born to Create!

[Armin Seeholzer]

My sharpest lens in my collection of LF lenses is my APO Symmar 210mm which is really deadliy sharp.
But you should also remember on the sentence of holy Ansel Adams, " better an unsharp picture of a clear idea then a very sharp picture of a fuzzi idea"
You should maybe start with a Imagon to just see there are more qualitys then just sharpness in many pictures!
Filmflatness and all this things are maybe more important then the killer lens itself!
Hope you get not sharpness sick, its a very dangerous illness and stops from creating pictures with a message sometimes;--)))
Armin

[Mirumir]

Thank you, Armin, for the response.
The Imagon-made kind of image is about the opposite to what I would like to continue achieving. There always stays on the possibility to soften the picture later, during darkroom printing, for example, if you need that effect. But it's impossible to restore all the tiniest details of the photograph's objects, if the unsharp optics haven't captured them initially. Don't get me wrong - this is not a "chase of sharpness" per se. I just know exactly what kind of visual image characteristics I'm looking for.
Best regards.

[claudiocambon]

Look at Kerry Thalmann's site. He has all sorts of recommendations in the 'future classics' section, and somewhere else there is a very analytical sharpness test that he did with someone else I believe, but I don't remember the URL right now.

[cblurton]

So, to summarize advice from this tread about how to get the highest sharpness and resolution without regard to the type or quality of the camera lens, one must consider:


Environmental considerations

Differences in air temperature across long distances
Ground vibration
Wind
Weather (rain, fog, etc.)

Considerations while shooting

Human focusing error
Film type
Depth of field
GG/film plane (mis)alignment
Inadequate tripod
Faulty or inappropriate cable release
Faulty film holder
Alignment of the front and back standards of the camera
Improper lens shading
Shutter vibration
Crappy filters

Post shooting

Developer choice
Developing technique
Enlarger lens
Enlarger aperture setting
Alignment of the enlarger
Focus point of the scanner (if used)

Lens quality? It is a wonder that any photograph is ever sharp.

[Mark Sawyer]

If you're going for a comprehensive list, I'd add "enlarger stability" to the post-shooting list. More important than a good tripod; camera exposures are often small fractions of a second, but under-the-enlarger exposures always run multiple seconds...

And "crappy filters" will apply to contrast filters in the darkroom as well...

And maybe keeping the lens clean, both shooting and enlarging...

And using each lens' optimum f/stop, both in the field and the darkroom. Or, on a related note, at least avoiding very small f/stops that will induce refraction problems as the light passes through the aperture...

[Mirumir]

Thank you, friends, for additional summarized recommendations.
Of course, all these sharpness-affecting considerations are always under serious attention.

GG/film plane alignment. After throughout camera cleaning, the ground glass and Fresnel lens have been set with their rugged surfaces turned to each other, Fresnel lens is closer to the camera lensboard, GG is farther from it. Please, correct me if that's wrong.

Regarding the tripod. BERLEBACH Mulda, with its proven sturdiness and ability to fix the shifts' knobs very tight, forms a solid, organic whole with 4x5" field camera.

Speaking of the cable release-related problems. When the frame is composed, shutter is cocked, the dark slide is taken out from the film holder and the cable release is in your hand, it is worth taking into account, I believe, to give the whole system a few seconds to become fully stabilized, before actually releasing the shutter.
The same care can be applied when you hold your enlarger's on/off switch and everything is ready to expose the paper.

Kerry Thalmann's site is really interesting, especially (in relation with this topic's main theme) its "Future Classics" section. Unfortunately, the resolution tests' sub-page is currently under construction.

And what's about the focus point of the scanner (if used)? How it can be adjusted - physically on the device itself or in the software? How to define the correct adjustment?

Thanks for your valuable observations.

[Gordon Moat]

Many cameras have the fresnel after the ground glass, but it depends upon manufacturer, since a few are the other way around. If you are using a 150mm to 180mm range lens, you might find you do better with critical focus without a fresnel. After I switched to a Satin Snow ground glass, I found using my 135mm and 180mm were actually easier with regard to focus. I got my Satin Snow through Badger Graphic Sales (http://www.badgergraphic.com/); it is the clipped corner style, and should fit many scanners.

The scanner is a much larger variable. If you are using a Creo, Screen Cezanne, or Fuji Lanovia flatbed, then you have a better guarantee of capturing all that is on the film. If you are using an older Linotype, then focus should not be much of an issue, though colour range might be, though it depends upon which Linotype. Any other scanners are much more of a crap-shoot on accuracy; low to mid range flatbed scanners are just not that accurate, nor that consistent.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[Robert A. Zeichner]

GG/film plane alignment. After throughout camera cleaning, the ground glass and Fresnel lens have been set with their rugged surfaces turned to each other, Fresnel lens is closer to the camera lensboard, GG is farther from it. Please, correct me if that's wrong.



I don't think you ever mentioned what camera you are using. Different manufacturers have different ways of handling Fresnel screens as Gordon pointed out. Many times, an unwitting tinkerer will add a Fresnel without understanding whether or not their particular camera was designed for one. If it wasn't, it's perfectly safe to place the Fresnel between the gg and your eyes. But, I've "fixed" a number of focus problems by removing a Fresnel that was added between the gg and the lens on camera not designed for this.

[Bernard Kaye]

Been away but better late than never: from far left field: Leitz (Leica) designed a lens for 4 x 5" use that they sold for their 35mm. Leica. It is now old if not vintage but is reverred by professional photographers for its sharpness, contrast and color rendition, particularly in 35mm. format when shooting down the center. It is the 135mm. f 4 Elmar, not the later Tele Elmar or earlier Hektor. I know that 35mm. format is not 4 x 5" but you have to see color transparencies projected (a good projector just like a good enlarger) or sizeable enlargements to appreciate this lens. I never saw one in a shutter but that is what John van Stelten (Focal Point) does. When a great Ektar exemplar comes along from 100mm. on up, test it, when properly mounted, etc., it will surprise you. Lens alignment is critical as is film flatness which is why 6 x 9cm. with the Kodak Medalist produced color and B & W negatives that could be pleasingly be enlarged to 16 x 24" and larger. When I sold foto stuff, seldom did I see a LF camera more than 6 to 12 months old that was not out of alignment and in need of TLC to bring it to specs.
Bernie

[paulr]

Leitz (Leica) designed a lens for 4 x 5" use that they sold for their 35mm.

that's strange. any lens design that can cover 4x5, even without movements, would have crappy sharpness by 35mm camera lens standards.

[Dan Fromm]

that's strange. any lens design that can cover 4x5, even without movements, would have crappy sharpness by 35mm camera lens standards.Have you asked the lenses? I have. It turned out that many of my lenses for formats larger than 35 mm are much better than crappy on 35 mm.

For example, my 210/9 Konica Hexanon GRII is sharper and contrastier at f/9, f/11, f/16, and f/22 at 1:2 and at ~ 30' than my 200/4 MicroNikkor AIS.

[Phil]

Here's a link to page for "Test Results - Large Format photographic lenses" done by Christopher M. Perez and Kerry L. Thalmann that someone mentioned:

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

Note: the Kodak 203mm f/7.7 Ektar data is at the bottom of the page.

[paulr]

Have you asked the lenses? I have. It turned out that many of my lenses for formats larger than 35 mm are much better than crappy on 35 mm.

For example, my 210/9 Konica Hexanon GRII is sharper and contrastier at f/9, f/11, f/16, and f/22 at 1:2 and at ~ 30' than my 200/4 MicroNikkor AIS.

you'll find isolated examples of severely bad 35mm lenses, but for the most part there's no comparison. if you look at MTF charts, you'll see that the manufactureres measure 35mm optics at 10, 20, and 40 lp/mm (vs. 5, 10, and 20 for LF) and that the modulation is as high or higher in the small format optics as the LF optics are at half the resolution.

it's a simple fact of lens design ... if you need five times the image circle size, you're going to have to compromise elsewhere.

[Dan Fromm]

Paul, its an empirical question. Please give concrete examples.

[paulr]

There are lots of MTF curves for 35mm lenses on photodo.com. they've reorganized the site so i don't have a specific page to link to.

schneider-kreuznach.com has mtf curves for all their current lenses.

a telling comparison is between schneider's LF optics, their digital optics, and their medium format optics for rollei. the smaller the format size, the greater the performance.

as an extreem example, a schneider engineer showed me examples of pictures made with a specialized lens that resolves 200 lp/mm at MTF-50. the catch is that the image circle is about 10mm!

[andrew vincent]

good lenses for medium format are only marginally better than good LF lenses in terms of lp/mm, whatever difference there is is usually not going to be recorded because of diffraction limits, film plane flatness, and all the other variables that keep real world resolution FAR below theoretical specs. All of these factors work in favor of 4x5 over medium format in terms of resolution because of film size. 35mm lenses cannot even come close to resolving whatever their theoretical limits are, so it's a bit of a red herring to even bother with them. Certainly no more than 100 lp/mm, and even if were to be a bit more, the difference in film size would squash it in any direct comparison. The only thing better is the new digital medium/large format lenses like Schneider's Digital Series, because then you're working with a whole different set of variables that are MATCHED to the vastly increased lp/mm (up to 200). So there, yes, I'd say you're seeing a lot more data.

[Ole Tjugen]

Time for another comparison shoot I think - I can try a Tessar, an Eurynar, a Hektor (Leitz) and an old Aplanat. I have them all in 135mm...

[paulr]

good lenses for medium format are only marginally better than good LF lenses in terms of lp/mm

well, those traditional lp/mm numbers are fairly useless because they don't tell you anything about actual image quality. Saying a lens resolves 100 lp/mm means little if you don't know the contrast it produces at that resolution. MTF measurements are based on how the eye actually sees sharpness, and they show lenses for smaller formats to be dramatically better than LF lenses. All of this takes into account diffraction limits, etc..

I'm not trying to imply that image quality of the whole system is better. the difference in film size more than makes up for the difference in lens sharpness. if it didn't, we'd all be using small format. My point was that it would be very strange if a large format lens design got repurposed for 35mm.

[Dan Fromm]

Paul, I've done tests on film.

I sometimes shoot flowers on 35 mm with the 210/9 GRII mentioned above. If I hadn't sold them -- I bought them as speculations, not as users -- I'd be happy using any one of the three dagor type 240/9 G-Clarons I've owned in the same application.

In fact, when it is practical I use a Nikon to do acceptance testing on lenses much longer than 100 mm that I intend to use on my 2x3 Graphics. On those cameras, all that matters for a lens made to cover a format larger than 2x3 is is the lens' performance near the center of the field. Testing on 35 mm gets the answer I need at a lower cost than testing on 2x3.

I've tried out a lot of lenses -- I don't own/move as many as Jim Galli, don't own quite as many as Ole Tjugen -- and I've got a number of good Nikkors for 35 mm. My best long lens for 35 mm is a Questar 700. On the emulsions I use at the apertures I shoot my keepers (these are the ones in my travel kit, plus a few others that for one reason or another usually stay home) do very well on 35 mm. I use few of them on 35 mm not because they're not good enough but because they lack modern conveniences like auto diaphragm. Also, since they aren't in Nikon F mount and don't have focusing helicals, using them in the field requires carrying a bellows, adapters, ...

All that said, one of my projects is making an adapter to let me hang a Nikon on a 2x3 Graflok back. This will let me use, e.g., my 480 Apo Nikkor on 35 mm.

Theorizing is fun, but it can't replace testing. If you haven't shot lenses for larger formats on 35 mm against lenses for 35 mm, you have nothing useful to say. Go test, and when you report back name names and report numbers.

[paulr]

If you haven't shot lenses for larger formats on 35 mm against lenses for 35 mm, you have nothing useful to say. Go test, and when you report back name names and report numbers.

uhhhh ... you're saying that your subjective results, with no stated methodology, are useful, while tests done with scientific riggor by optical engineers are not?

i think all you can reasonably report on is what things look like to you, under the specific conditions you tested for. but the OP is about what lens has the highest sharpness and resolution, which is a question that can often only be resolved in a laboratory setting. and my response was to a post suggesting that a large format design was repurposed by leitz for 35mm, which is not (in the opinions of the engineers at companies like schneider at least) a good idea.

[Ole Tjugen]

Nevertheless the Leitz Hektor 135mm f:4 was designed for 9x12cm, and adapted for 35mm by the addition of a spacer tube with helical focus and a Leica thread on the end. :)

[Dan Fromm]

uhhhh ... you're saying that your subjective results, with no stated methodology, are useful, while tests done with scientific riggor by optical engineers are not?

i think all you can reasonably report on is what things look like to you, under the specific conditions you tested for. but the OP is about what lens has the highest sharpness and resolution, which is a question that can often only be resolved in a laboratory setting. and my response was to a post suggesting that a large format design was repurposed by leitz for 35mm, which is not (in the opinions of the engineers at companies like schneider at least) a good idea.Friend, I can tell the difference between excrement and shoe polish. Can you?

The OP's question seems pretty naive, perhaps even idiotic. If I'd thought the moderators would let me say this, I'd have said it near the start of this thread.

Your reliance on low frequency MTFs to estimate how well fine detail can be captured on film seems about as intelligent as the original question. As I read published MTF curves, they're good for little but deciding how crazy coverage claims are. Look, for example, at Schneider's MTF curves for Xenars and G-Clarons. They show minimal contrast at low spatial frequencies at the limit of claimed coverage. Giggle-making.

You have to remember that although more aerial resolution at good contrast is preferable to less, what matters is resolution on film or as captured by the sensor. That's why the best way to find out what a lens will do in use is to use it.

As for my test procedures, they may seem informal to you but the rankings they produce are consistent and repeatable. I use the same emulsion, same shutter (to eliminate the effects of variations between shutters), and same targets for my testing. My targets have features with variable spacing, so I can do better than simple go/no go testing based on "resolves some level of fine detail." Different targets at different distances.

[paulr]

FYour reliance on low frequency MTFs to estimate how well fine detail can be captured on film seems about as intelligent as the original question. As I read published MTF curves, they're good for little but deciding how crazy coverage claims are.

perhaps in your experience; but every time i've seen a visible difference in lens quality (between two lenses, or in the same lens at different apertures, magnifications, or angles off axis) it's corresponded to a large difference in tested MTF. small differences in tested MTF are often not noticeable to me subjectively, telling me that the test procedures are probably (and not surprisingly) more sensitive than my own variable-ridden tests.

The larger point is that the difference in MTF between lenses of comparable quality designed for different formats is not a subtle one. If you compare, for example, schneider's current LF optics with their MF optics and their digital optics, the differences are huge, and correspond directly to the size of coverage.

In practical terms I'd agree with you, that what ultimately matters is what you see on the print. But I'm forever suspicious of any attempts to make universal statements about optical quality based on home grown tests.

[scott_6029]

Sure, why not a 180mm Caltar II N - about <$300 used..check out my color images on my website taken with this 'cheap' inexpensive lens. I have made lots of 16x20 and 30x40's from 4x5 transparencies with this lens...

[sanking]

For more information on this subject I recommend Image Clarity: High-Resolution Photography, by John B. Williams, published by Focal Press.


Sandy King

[Mirumir]

"...I don't think you ever mentioned what camera you are using..."
I bought LINHOF Technika 4x5" (flat front lid, serial No.316**) already with Fresnel screen installed. When all and every its part has been cleaned out, I assembled the camera over again. Assembling the rear standard, I had to measure the distance between the film plane (film holder half-inserted, dark slide taken out) and the square metal base, to which the film holder (or the wringing-out camera back) is pressed down. The image forms on the matt (frosted) surface of the GG. So, it has to be set in such a way that the distance between this matt surface and the rear camera standard's square base was identical to the distance between the film plane and that metal square base (sorry, don't know how to name this part correctly). The only position the distance is the same - when the ground glass and Fresnel screen are turned with their rough surfaces to each other, Fresnel is closer to the camera lensboard, GG is farther from it.
Interestingly, what year of manufacturing this particular camera is dated from?

According to "Tests Results - Large Format Photographic Lenses" done by Christopher M.Perez and Kerry L.Thalmann (www.hevanet.com/cperez/testing), there is almost no LF lens, even the modern one, resolving more than 80 lines per mm. That's strange.
I had two LF lenses measured for their resolution on the collimator (long tube-like industrial optics resolution measurement device). For example, SCHNEIDER Xenar 105mm/f.3.5 gives up to 189 lines (not lines pairs!) per millimetre as its nominal optical resolution, and up to 238 lines/mm as the resolution on the overtones. VOIGTLANDER Heliar 150 mm/f.4.5 is capable to deliver near 170 lines/mm, but these lines, visible on the collimator through the Heliar, turn out to be slightly softened. Probably Heliar designers have provided this effect intentionally.
An optics specialist, who helped to test these lenses, right after the Heliar has measured one cinematographic, Planar-type lens (do not know its official brand and name). It has been capable to resolve 600 (yes, six hundred) lines per mm!
Please, note - these values are not "theoretical", they were REALLY visible.
Additionally, a few years ago I performed a resolution test of mentioned above SCHNEIDER Xenar 105mm/f.3.5 on the film (KODAK T-Max 100), having photographed special diagrams with those lines. On the frame taken at f/stop 16, the part of the diagram showing 100 lines/mm is clearly visible, when the negative is enlarged. The film has been developed in AGFA Rodinal, diluted 1:100.

Cleanest wishes.

[Dan Fromm]

Do you know the difference between aerial resolution and resolution on film? Resolution on film is what matters.

600 lp/mm aerial resolution is impossible at apertures smaller than f/2.5. Be practical, person! There are very few f/2.5 and faster lenses that will cover 4x5, let alone larger formats. I had one such, a 6"/1.9 Dallmeyer Super Six. Super Sixes aren't nearly as sharp as you want wide open, and the 6 incher, in barrel, weighs nearly 4 pounds.

100 lp/mm on film at f/16 is highly unlikely. That's the theoretical limit, in practice not quite attainable, for aerial resolution at that aperture. Resolution on film is never as high as aerial resolution. In some very serious tests with, among other emulsions, TP, and very good lenses, Modern Photography magazine just barely got 100 lp/mm on film at around f/5.6.

This is not intended to be insulting, but you worry too much. Get over your silly obsessions and go shoot. If you can't make 4x5 negatives that print well as large as you need, go up in format.

Also, buy a copy of John Williams' book Image Clarity. And read it closely.

[Gordon Moat]

The best of modern transparency films can barely resolve 90 lp/mm under ideal conditions, regardless of lens. If you are shooting B/W films, then you might be able to do better, but there are many factors to consider.

When you look at C. Perez (http://www.hevanet.com/cperez/testing.html) test results, you need to realize that almost all those lenses were tested at what would be considered normal working apertures, typically f11, f16, and f22. You can better those numbers by shooting at f8.0, or even f5.6, but then you create another problem: very limited Depth of Field. I shoot wide open to f8.0 quite often, but only the very short region within the DoF is sharp, everything else is unsharp (or defocused). Since you have read the test results, you should also read the Comments (http://www.hevanet.com/cperez/results.html) that went with them, since that explains things better.

Also, for a 6x7 (cm) medium format camera, remember that the film is less than half the area of a 4x5. So you would need (more than) twice the resolution capability to match what you could do with a 4x5. So to match 60 lp/mm, a figure not too tough in 4x5 imaging, you would need better than 120 lp/mm on the film from medium format; even a Mamiya 7 would struggle to reach that with their best lenses, and certainly not on colour transparency film.

The last issue is film flatness. While we can assume that our holders are fairly good, the reality is that the film will rarely be perfectly flat. So your adjusting your Linhof is not a bad idea, but you will still need to deal with film flatness.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[paulr]

Do you know the difference between aerial resolution and resolution on film? Resolution on film is what matters.

neither matters.

unless you're operating a spy satellite, what maters, equally, is the MTF performance of the film and the MTF performance of the lens.

what does "resolves 80 lp/mm" matter, or even mean? if an optical system reproduces detail at that frequency at 5&#37; contrast, it will be detectible but not useful. it will not in any way contribute to a picture looking detailed or sharp.

if you wantt a picture that looks sharp, you're going to need the print to reproduce detail in the 1 lp/mm to 5lp/mm range at a high contrast: ideally 50% or more. predicting this requires multiplying the MTF at the relevant frequency of every link in the optical chain: taking lens, film, enlarging lens, paper.

if your prints are 10X enlargements, that means you need to be concerned with the performance of everything in the 10lp/mm to 50 lp/mm range.

all the talk of resolution limits is essentially worthless in predicting the subjective sharpness of a print. optical systems (including the human eye) just don't work that way.

John Williams' Image Clarity book spells all this out clearly, in fact, with excellent examples. A great one is two images side by side, one that produces much higher resolution than the other, but at lower MTF. the low res, high MTF version is dramatically sharper and better looking.

[erie patsellis]

"Assembling the rear standard, I had to measure the distance between the film plane (film holder half-inserted, dark slide taken out) and the square metal base, to which the film holder (or the wringing-out camera back) is pressed down. The image forms on the matt (frosted) surface of the GG. So, it has to be set in such a way that the distance between this matt surface and the rear camera standard's square base was identical to the distance between the film plane and that metal square base (sorry, don't know how to name this part correctly). The only position the distance is the same - when the ground glass and Fresnel screen are turned with their rough surfaces to each other, Fresnel is closer to the camera lensboard, GG is farther from it.

Did anybody else catch this, the solution may simply be not understanding that when you put the GG behind the fresnel, you have to offset the GG by 1/3(?) of the thickness of the fresnel, if memory serves me. Have you tried not using the fresnel, just the GG, and getting the T dimension dead on? would resolve so many problems easily.


erie

[sanking]

neither matters.

unless you're operating a spy satellite, what maters, equally, is the MTF performance of the film and the MTF performance of the lens.

what does "resolves 80 lp/mm" matter, or even mean? if an optical system reproduces detail at that frequency at 5&#37; contrast, it will be detectible but not useful. it will not in any way contribute to a picture looking detailed or sharp.

if you wantt a picture that looks sharp, you're going to need the print to reproduce detail in the 1 lp/mm to 5lp/mm range at a high contrast: ideally 50% or more. predicting this requires multiplying the MTF at the relevant frequency of every link in the optical chain: taking lens, film, enlarging lens, paper.

if your prints are 10X enlargements, that means you need to be concerned with the performance of everything in the 10lp/mm to 50 lp/mm range.

all the talk of resolution limits is essentially worthless in predicting the subjective sharpness of a print. optical systems (including the human eye) just don't work that way.

John Williams' Image Clarity book spells all this out clearly, in fact, with excellent examples. A great one is two images side by side, one that produces much higher resolution than the other, but at lower MTF. the low res, high MTF version is dramatically sharper and better looking.


I read John Williams' book carefully but certainly did not take from it the idea that resolution does not matter. What Williams says is that it is a useful procedure that accurately measures a systems capacity to produce fine detail and that it is an important tool for photographers. He does point out some limitations of resolution tests, i.e. they are subject to variations because of individual judgment, and the fact that the ability to capture detail does not always correlate with a system's ability to produce good edge contrast.

However, I would hold that a lens that can capture fine detail *and* produce good edge contrast is a better lens that does only one of the two so resolution tests are not a waste of time.

Regarding previous comments about Mamiya 7 versus 4X5 it should be noted that the magnification factor is more important in determining the capacity of these two systems to record detail than the total area of the negative. The long dimension of a 6X7 negatives is 55% of the long dimension of 4X5 and to capture the same amount of detail a 6X7 system would only need to resolve about 1.8 times as much as a 4X5 system, not more than twice as was earlier stated. Given the fact that it is not at all uncommon for lenses of the Mamiya 7 system to resolve over 100 lppm I think it not unreasonable to suggest that in many circumstances Mamiya 7 is capable of producing as much detail as 4X5 when using lenses with similar angles of coverage on the two formats. And especially so given the fact that for equal DOF the Mamiya 7 lenses can be used at apertures where diffraction is much less. There are of course other factors that determine final image quality, but if the issue is detail and nothing more my own experience is that Mamiya 7 is very close to 4X5, and may actually beat it in some circumstances.

Sandy King

[paulr]

I read John Williams' book carefully but certainly did not take from it the idea that resolution does not matter.

it's not that it doesn't matter, but that it's a small part of the puzzle of what makes an image look sharp and detailed.

while there aren't any standards for determining the finest resolution that a lens can reproduce, it usually comes down to the maximum resolution that the lens can render at a few percent contrast (the minimum that the eye can discern with a high contrast test target). and this number only sometimes correlates to how high the contrast is at the resolutions that matter most for perceived quality.

it's a bit like buying a computer based on the clockspeed of the processor alone, without knowing anything else about the design. it matters, but if it's all you know, you don't know much.

resolution numbers also tempt people to think of the image chain in terms of weakest links ... like if the film resolves x lp/mm, then that's the limit of the whole system, and you won't see the benefit of a lens that resolves more than x. which of course isn't how it works at all.

[sanking]

it's not that it doesn't matter, but that it's a small part of the puzzle of what makes an image look sharp and detailed.




I agree that detail is a part of the puzzle, but IMO it is not always a small part. In contact prints and in moderate magnifications from LF film resolving power is probably not as as important as edge contrast. But as the amount of magnification increases the amount of detail in the negative becomes a very important issue if critical sharpness at a standard viewing distance is to be retained.

Sandy King

[Gordon Moat]

Hello Sandy,

A question for you.




. . . . . .

Regarding previous comments about Mamiya 7 versus 4X5 it should be noted that the magnification factor is more important in determining the capacity of these two systems to record detail than the total area of the negative. The long dimension of a 6X7 negatives is 55% of the long dimension of 4X5 and to capture the same amount of detail a 6X7 system would only need to resolve about 1.8 times as much as a 4X5 system, not more than twice as was earlier stated. Given the fact that it is not at all uncommon for lenses of the Mamiya 7 system to resolve over 100 lppm I think it not unreasonable to suggest that in many circumstances Mamiya 7 is capable of producing as much detail as 4X5 when using lenses with similar angles of coverage on the two formats. And especially so given the fact that for equal DOF the Mamiya 7 lenses can be used at apertures where diffraction is much less. There are of course other factors that determine final image quality, but if the issue is detail and nothing more my own experience is that Mamiya 7 is very close to 4X5, and may actually beat it in some circumstances.

Sandy King

I am using Linhof 56x72mm for my 6x7 comparison. When I place two frames from that on top of a single 4x5 frame, there is still room left over on the 4x5 frame, hence where I get the more than 2x difference. So is the Mamiya 7 frame size larger than the Linhof 6x7 frame? Or is there some other math I am missing here? Thanks in advance.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[sanking]

Hello Sandy,

A question for you.





I am using Linhof 56x72mm for my 6x7 comparison. When I place two frames from that on top of a single 4x5 frame, there is still room left over on the 4x5 frame, hence where I get the more than 2x difference. So is the Mamiya 7 frame size larger than the Linhof 6x7 frame? Or is there some other math I am missing here? Thanks in advance.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)



Gordon,

For the earlier comment I just based my figure on the difference between nominal values of 6X7cm and 5".

However, I just measured the actual long dimensions of some of my Mamiya 7 negatives and 4X5 negatives, and actual is even more favorable to the 6X7 format than nominal. My Mamiya 7 negatives are a full 7cm on the long dimension, whereas the 4X5 negatives are only 12cm on the long dimension. In other words, the 6X7 negative is 58% as long as the 4X5 negative, so resolution with the Mamiya 7 would only need to be 1.7 times 4X5 to give the same detail on film.

If you are actually getting 72mm with the Linhoff your comparison would be even more favorable, assuming equal lens quality. However, I really doubt that anything else out there in medium or LF will equal Mamiya 7 optics.

OK, that is how I did the calculations. Am I making a conceptual mistake of some sort?

Sandy King

[sanking]

resolution numbers also tempt people to think of the image chain in terms of weakest links ... like if the film resolves x lp/mm, then that's the limit of the whole system, and you won't see the benefit of a lens that resolves more than x. which of course isn't how it works at all.

Paul,

Williams makes exactly that point, i.e. that the weakest link in the image chain is the one that ultimately determines the amount of information that can be conveyed.

In the chapter on the Theory of Image Degradation he write: "It can be seen from the degradation equation that the minimum size of the photographic-spread function and the greatest image quality a system can produce will always be limited by the largest component-spread function in the system. When one spread component system is conspicuously larger than others, it imposes a resolution limit on the system."

Sandy King

[Gordon Moat]

Okay, using the long dimension:

3.175x for 11.9" by 15" print from 4x5
5.3x for 11.7" by 15" print from 4x5

So 1.67 difference. Assuming 60 lp/mm within reach from a 4x5, then a Mamiya 7 lens would roughly match at 100 lp/mm. I think that is within reach with most B/W films, based on C.Perez Tests (http://www.allgstudio.com). I have not seen Fuji Astia 100F or Kodak E100G (supposedly the two best) resolve much beyond 90 lp/mm (Erwin Puts published in LFI magazine a few years ago), so the comparison on colour film might be tougher.

Anyway, the comparison is very close, with 4x5 staying within the capabilities of the film though lens limited, and the Mamiya 7 lens being limited by the film. Then it would be a comparison on other aspects, such as movements capability on a 4x5, compared to arguably better edge resolution on Mamiya 7 lenses.

If the OP is still reading, this might give him another idea. If he does not need movements in the camera, perhaps a Mamiya 7 system might work better for him. With B/W film, he could potentially do better than most 4x5 systems and lenses.

Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

[sanking]

Anyway, the comparison is very close, with 4x5 staying within the capabilities of the film though lens limited, and the Mamiya 7 lens being limited by the film. Then it would be a comparison on other aspects, such as movements capability on a 4x5, compared to arguably better edge resolution on Mamiya 7 lenses.


Ciao!

Gordon Moat
A G Studio (http://www.allgstudio.com)

That is pretty much the conclusion I reached. Course, you must also factor grain in there since that is going to be 1.7 times as large with 6X7 as with 4X5, assuming the same film.

You could actually get the same DOF at equal aperture by using a much finer grain film with 6X7, and at this point I think you are about par with the two formats.

In order to get the equivalent of 100 lppm of detail out of a 6X7 negative you will need a scanner capable of "effective" resolution of 5000 ppi. You will need an Imacon or drum scanner for that. This assumes of course that you want to print at the highest possible size and still retain about 5 lppm of detail in the print (which would be about 36"X44"). Up to 18X22" effective scanning resolution of about 2540 ppi would be enough.

Sandy King

[dslater]

well, he was also comparing enlargements to contact prints, which is probably a bigger variable than the lenses, and almost as big a variable as the format difference.

I don't think you can conclude much at all about lenses from a comparison like that, except that contact prints from old lenses can look great (not really a news flash!)

He is not trying to make a comparison about lenses - the point he's making is that if you want sharper prints, then move up to a larger format so you enlarge your negatives less or make contact prints.

[Sheldon N]

Of course, the discussion of MF lenses having higher resolution goes out the window when simple movements like tilt come into play.

If you are shooting with a mild wide angle lens and taking a picture with a simple flat-foreground-to-infinity composition, having front tilt makes all the difference in the world.

To get an acceptably sharp (sufficient DOF) 16x20 print with everthing from 5 ft to infinity sharp, you need to stop down to roughly f/22 (assuming a 50mm lens on 6x7) to get everthing within DOF. At f/22, you are diffraction limited to roughly 60 lp/mm on film resolution so the "better" medium format lens has no advantage over 4x5, which can shoot at f/16 with front tilt and also put 60 lp/mm on a larger piece of film.

If you make the lenses longer, then the advantage to having tilt on 4x5 is even greater, since the MF lenses just have to stop down farther to get sufficient DOF.

This advantage doesn't hold true for all compositions and all scenes, but I would venture to say it is the primary reason why most of us choose large format instead of MF for our primary landscape camera.

[sanking]

This advantage doesn't hold true for all compositions and all scenes, but I would venture to say it is the primary reason why most of us choose large format instead of MF for our primary landscape camera.

I use LF primarily for perspective control, not control of sharpness.

With regard to the specific scenario you mention, let me throw in this. Some years ago I heard the photographer David Muench discuss his working habits on 4X5 with this type of near to far scene. My memory is that he stated that with near distance to far distance scenes he almost always relied on stopping the lens down to get adequate DOF rather than using tilts. Reasoning was that the use of tilts, which does indeed give sharpness from near to far on one plane, may grossly distort images on the other plane.

Sandy King

[paulr]

Paul,

Williams makes exactly that point, i.e. that the weakest link in the image chain is the one that ultimately determines the amount of information that can be conveyed.

In the chapter on the Theory of Image Degradation he write: "It can be seen from the degradation equation that the minimum size of the photographic-spread function and the greatest image quality a system can produce will always be limited by the largest component-spread function in the system. When one spread component system is conspicuously larger than others, it imposes a resolution limit on the system."

Sandy King

The flawed thinking I'm talking about is this: people assume that if you've identified the weakest link in the image chain, then the other (stronger) links cannot degrade the image farther. They can. All parts of the optical system degrade the image. Higher quality parts of the system degrade it less. Final image quality is not determined by the weak link, but by the sum total degradations of all the links.

There is NO WAY to predict the optical quality of an optical system by looking at resolution numbers of its individual parts (however you choose to measure them). Unless one of the parts is radically weaker than all the others put together. But MTF, since it shows percentage of contrast lost, makes this easy. you just multiply.

Williams goes into some detail on this, but all it takes is general understanding of MTF theory see how it all works.