35mm lens resolution measurements

[Diffraction]

Hi all,

this may be a contentious thread but I am genuinely curious to see the responses.

What I'm curious about is whether there are any actual lens resolution comparisons for 35mm out there. For medium format, there's the Hevanet website: https://web.hevanet.com/cperez/MF_testing.html . I found the results there quite interesting; they seem to suggest that for medium format, there are differences among the lenses, with e.g. the Mamiya 7 lenses outresolving Bronica SQ lenses. Of course, whether the differences matter very much in practice is a separate question, but I still found it interesting.

For 35mm, I haven't found any such comparisons. Does anyone know of one? I'd be interested because there are so many subjective comparisons out there, claiming this or that lens is great and very sharp, but it's hard to tell without actual measurements. Is there a reason people don't do this? Is the limitation in 35mm generally just the small size of the negative? It feels like there should still be differences, especially wide open...

 

[Nicholas Lindan]

In the old days the print magazines used to print the results of their MTF lens tests. Lens makers who tested positively reprinted the results in their ads, those who tested poorly pooh-poohed the whole idea of judging a lens by resolution.

I don't know of any website that maintains an optical laboratory that could bring back the practice of laboratory bench testing. Now it is all opinion and rumor with little attempt at objectivity. Anyhows, I hear objectivity is now a disgraced concept - Pol Pot would be proud.

Win some with the internet, lose some with the internet.

 

[wiltw]

As mentioned, Modern Photography used to print very in depth analyses of lenses...
true FL, true max aperture size, lens resolution tests.
In those days, a lgood ens typically measured about 48-64 ll/mm, really great lenses were 84 ll/mm, and the rare truly exception lens was 100-120 ll/mm
For OM mount lenses, one site carried many of the Modern Photography results as a compilation
https://potsun.wordpress.com/2005/10/28/modern-photography-zuiko-lens-tests/

 

[AgX]

Comparisons are only worthwhile if all the tests are made the same way.

 

[warden]

I think Roger Cicala is as close as we get right now as far as I know, but I haven't seen his work presented like the OP's list. Roger's work is more in depth than the MF tests for sure.

https://www.lensrentals.com/blog/2018/11/using-rapid-mtf-testing-how-we-test-monitor-our-lenses/

https://www.lensrentals.com/blog/20...n-17-28mm-and-28-75mm-f2-8-di-iii-rxd-lenses/

 

[ciniframe]

“Is the limitation in 35mm generally just the small size of the negative?”
Certainly plays a roll in how much information can be stuffed into a final print. Yes, yes, I know, some 35mm have been enlarged to the size of a highway billboard, but you are looking at them from several hundred feet away.
Of curiosity, are you asking because you wish to make large prints that still hold fine detail even when examined at a close viewing distance?

 

[ic-racer]

There is MTF information on the internet for 35mm camera lenses. It takes some searching. In the 'pre-MTF' era, resolution tests of 35mm camera lenses were published in the popular photography magazines. For example:

 

[ic-racer]

Independent lens analysis obtained form the internet:

 

[ic-racer]

Some manufacturers also provided MTF information for their 35mm camera lenses that can be obtained with internet searching.

 

[Nicholas Lindan]

I think Roger Cicala is as close as we get ...

Well, I'm impressed. Thanks for pointing out the web site.

 

[faberryman]

I remember reading lens tests in Modern Photography and Popular Photography back in the 1970s and 1980s. Leica lenses usually, but not always, came out on top. One brand would have the best 28mm, another the best 35mm, another the best 50mm, but you were stuck with whatever your brand’s offerings were because mounts were not interchangeable. And it didn’t really matter because all of them were pretty close to one another in performance, and lens resolution wasn’t what was holding your photography back anyway. But lens tests gave you something to obsess over so they served their purpose. Still do, I guess.

 

[warden]

Well, I'm impressed. Thanks for pointing out the web site.

My pleasure. I think they dig deeper than anyone.

 

[Mark Crabtree]

Tests are only as good as the methodology, and often interpreting the results requires detail of the methods. How to deal with curvature of field for instance. A lens may be extremely sharp at the edges but not at the same plane of focus as the center, for instance the 2nd version Leica Summilux. You can present accurate information to make that lens look like a dog or a hero.

Many amateur tests end up being a test of focus accuracy more than lens performance. Unless you design your tests to cover misfocus and camera/lens/film focus calibration you are only getting useful information about how that particular system functions for that particular photographer in that particular situation.

 

[warden]

Tests are only as good as the methodology, and often interpreting the results requires detail of the methods. How to deal with curvature of field for instance. A lens may be extremely sharp at the edges but not at the same plane of focus as the center, for instance the 2nd version Leica Summilux. You can present accurate information to make that lens look like a dog or a hero.

Many amateur tests end up being a test of focus accuracy more than lens performance. Unless you design your tests to cover misfocus and camera/lens/film focus calibration you are only getting useful information about how that particular system functions for that particular photographer in that particular situation.

I agree. The MF test the OP linked to shows the limitations of this kind of experimenting. The tester apparently couldn't focus the Makina or had a very poor or damaged copy, but since he only tested one unit no conclusion can be made other than the question mark he delivered in the notes section. Ditto the Yashicamat, which is known to have a quality lens especially when stopped down a little, but look at the results: the one he tested showed a significant problem, performing adequately wide open and actually getting worse when stopped down which indicates a problem with the lens, camera, testing methodology or all of the above. Another question mark was offered in the notes since there were apparently no other Yashicamats to test.

Newcomers to reading this sort of lens testing might be forgiven for thinking Makinas and Yashicamats were supplied with crap lenses, but that is most certainly not the case.

 

[Mark Crabtree]

I agree. The MF test the OP linked to shows the limitations of this kind of experimenting. The tester apparently couldn't focus the Makina or had a very poor or damaged copy, but since he only tested one unit no conclusion can be made other than the question mark he delivered in the notes section. Ditto the Yashicamat, which is known to have a quality lens especially when stopped down a little, but look at the results: the one he tested showed a significant problem, performing adequately wide open and actually getting worse when stopped down which indicates a problem with the lens, camera, testing methodology or all of the above. Another question mark was offered in the notes since there were apparently no other Yashicamats to test.

Newcomers to reading this sort of lens testing might be forgiven for thinking Makinas and Yashicamats were supplied with crap lenses, but that is most certainly not the case.

It is incredibly hard to do these tests in a meaningful way. Tests with oddly high spread of results like you mention automatically make me wonder about the procedure. I think you can probably trust the high numbers as being meaningful, but have no way to know about what low numbers mean. In addition to the factors I mentioned before, there is film flatness to factor in with medium format.

The old Pop or Modern extensive test of 35mm normal lenses always impressed me and you can find the results online, though it takes some hunting. They included measures for decentering and focus shift which was reassuring. Focus shift is always a factor with fast spherical lenses, plus there is really no good way to focus them entirely accuratelly at full aperture other than trial and error. Some testing methods used an array of targets slightly offset so as to catch the actual best focus point.

I assume the computerized testing gear used by folks like Roger Cicala deal with most of these issues, though there are still some decisions to be made about things like field flatness.

 

[Jim Jones]

While stationed at a fairly remote Navy base in the 1960s, I improvised a test based on a system used by Leica. The target was a microfilmed copy of the complete Bible on one small piece of film. This contained finer detail than any readily available lens for consumer 35mm cameras can resolve. The image was projected onto a large plain flat screen with a slide projector modified to accept a variety of ordinary camera lenses. This test does not provide numerical results for comparison with other lenses. However, it is very quick to do and it easily separates the best from the merely adequate lenses. About 35 lenses were tested. Three of the distinctly best ones were the Leitz Elmar 50mm f/2.8, the El-Nikkor 50mm f.2.8 enlarging lens, and the 45mm f/2.8 GN-Nikkor pancake lens which was designed for convenient flash photography. An early Nikkor 20mm f/3.5 that had to be used with mirror lock-up was extremely sharp in the center of the image with much less sharpness in the corners. The 45mm f/2.8 pancake lens and the Elmar were only four element lenses while the others were more complex. These tests were only for the ability to resolve fine detail and for field curvature, not for other important lens characteristics.

 

[Paul Howell]

Leica and others tested with microfilm, my instructor in college would tell us that a lens only needed to be as good as Trix or GAF 500, which is all we shot in the PJ program.

 

[George Mann]

I have been using a lens for 40 years that has outresolved everything I have ever thrown at it, digital (D850) or film (Pan-X).

I never felt the need for anything "better".

 

[alanrockwood]

There used to be a lens test kit available for people to do their own lens testing. I think Modern Photography sold it, or maybe it was from Edmond Scientific, I don't remember. Anyway, it had some resolution targets in the kit, and a viewing lens for looking at the negatives, along with a set of instructions. It specified Panatomic-X film for the test medium. I believe they also had instructions for testing shutter speeds using a TV set.

 

[Jim Jones]

Over the past many decades there have been many lens test charts. Probably the one most often used is the 1951 USAF lens test chart. Some information on downloading the chart is available at https://jimdoty.org/Tips/Equipment/USAF_Test/usaf_test.html and elsewhere.

 

[faberryman]

Over the past many decades there have been many lens test charts. Probably the one most often used is the 1951 USAF lens test chart. Some information on downloading the chart is available at https://jimdoty.org/Tips/Equipment/USAF_Test/usaf_test.html and elsewhere.

Once you test your lens, then what?

 

[BradS]

Unfortunately, virtually all published lens tests are done on sample size one (or, at very best, n<10) and are therefore completely meaningless.

 

[Dali]

Unfortunately, virtually all published lens tests are done on sample size one (or, at very best, n<10) and are therefore completely meaningless.

I agree 100%. Most of lens tests mention the lens serial number. Guess why...? But readers does not pay attention to such limitation, eager they are to find the next jewel to add to their collection.

35mm lenses were measured like any other lense regardless of the negative format, being with MTF or resolution chart and results were heavily published. Always the same BS on a different form.

Once you know that a lense resolved x lpm with x% contrast, how does it translate in real life? Nobody knows for sure...

After all these years, I am still waiting for a site or a magazine ranking lenses in 3 categories: Good, Average, Bad, from a global perspective (resolution at various distance, contrast, vignetting, distorsion, color accuracy, flare resistance, you name it) assuming that the tested lens has been correctly assembled. Instead, we have infotainment and smoke screen.

 

[Dali]

https://www.lensrentals.com/blog/2021/04/selecting-the-proper-brick-wall-for-photographic-tests/

 

[BrianShaw]

Unfortunately, virtually all published lens tests are done on sample size one (or, at very best, n<10) and are therefore completely meaningless.

Assuming that there is SPC in place at manufacturing, there could be a bit more validity than you’re giving credit for. QC done right generally results in a fairly stable product. Statistically speaking, though… you’re quite correct… as you already know.