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  1. #11
    RalphLambrecht's Avatar
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    Quote Originally Posted by jpberger View Post
    ...But just to be obtuse- aren't the best 35 mm lenses like the asph 90 summicron diffraction limited at f/4 or something insane?
    If I'm not mistaken, f/4 has a diffraction limit of 369 lp/mm at 555 nm. Measured on an optical bench, the Summicron may reach that performance in air with a high-contrast target, but combined with a film limited to 100 lp/mm, with normal-contrast scenes, this performance drops to a more realistic and still ambitious 97 lp/mm.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  2. #12
    Sirius Glass's Avatar
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    Quote Originally Posted by RalphLambrecht View Post
    I think the equation, shown in the attachment to my post above, proves this statement wrong. Improving on any part of the chain will improve the overall performance. No link of the chain is an absolute limiter.
    However, to get the maximum bang for the buck, one should work on the weakest link. If one part is limited to 60 lp/mm moving from a 120 lp/mm lens to a 150 lp/mm lenses will not show the improvement one would expect [If they did not understand the physics of the image chain.]

    Steve
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  3. #13
    RalphLambrecht's Avatar
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    Quote Originally Posted by Sirius Glass View Post
    However, to get the maximum bang for the buck, one should work on the weakest link. If one part is limited to 60 lp/mm moving from a 120 lp/mm lens to a 150 lp/mm lenses will not show the improvement one would expect [If they did not understand the physics of the image chain.]

    Steve
    Correct.

    Here is the scary reality of image chains:

    camera lens............185.0 lp/mm (diffraction limited at f/8)
    film.......................150.0 lp/mm (only possible with high-contrast scenes)
    enlarger lens.......... 185.0 lp/mm (diffraction limited at f/8)
    aerial image.............98.6 lp/mm (as a result of the above)

    print magnification......8.5 (35mm negative on 8x10, no cropping)
    paper....................100.0 lp/mm (paper resolution is fairly high)
    total system............ 11.5 lp/mm (total system resolution)

    11.5 lp/mm is not bad, but standard and critical near-vision resolution of the human eye is considered to be 7 and 20 lp/mm, respectively. In other words, the best taking lens, combined with the best enlarging lens, combined with fine-grain film and a high-contrast target, is just about good enough to make a good 8x10 print from a 35mm negative.

    This is why moving to medium format gives such a jump in print performance. The equipment is not of higher quality, but the reduced necessity for enlarging gives a significant boost in print resolution.

    Unfortunately, expecting another such jump in quality by moving to large-format equipment results in a disappointment. Not that it's not there, but our eyes cannot appreciate it, unless large prints are made and viewed close up.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  4. #14
    ic-racer's Avatar
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    All theoretical thinking aside, actual tests of popular 35mm lenses were conducted by Modern Photography magazine in the 70s. I have many of the magazines and there is a lot of data there. One of these days I should compile it all into a nice table like the one that is out there for large format lenses.

    I can summarize my years of reading the test reports in that most all the 'name brand' 35mm SLR lenses performed about the same at f8.

    When wide open, the results were all over the place, though, now days, a 'bad' wide open performance may actually be sought for its aesthetic qualities.

    Also, from what I remember, all the Leica M lenses had way more contrast, and usually better sharpness when compared to the others.

  5. #15
    Sirius Glass's Avatar
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    Quote Originally Posted by RalphLambrecht View Post
    Correct.

    Here is the scary reality of image chains:

    camera lens............185.0 lp/mm (diffraction limited at f/8)
    film.......................150.0 lp/mm (only possible with high-contrast scenes)
    enlarger lens.......... 185.0 lp/mm (diffraction limited at f/8)
    aerial image.............98.6 lp/mm (as a result of the above)

    print magnification......8.5 (35mm negative on 8x10, no cropping)
    paper....................100.0 lp/mm (paper resolution is fairly high)
    total system............ 11.5 lp/mm (total system resolution)

    11.5 lp/mm is not bad, but standard and critical near-vision resolution of the human eye is considered to be 7 and 20 lp/mm, respectively. In other words, the best taking lens, combined with the best enlarging lens, combined with fine-grain film and a high-contrast target, is just about good enough to make a good 8x10 print from a 35mm negative.

    This is why moving to medium format gives such a jump in print performance. The equipment is not of higher quality, but the reduced necessity for enlarging gives a significant boost in print resolution.

    Unfortunately, expecting another such jump in quality by moving to large-format equipment results in a disappointment. Not that it's not there, but our eyes cannot appreciate it, unless large prints are made and viewed close up.
    Thank you, that was well stated. The last paragraph hit home because I keep thinking about going into LF.

    Steve
    Warning!! Handling a Hasselblad can be harmful to your financial well being!

    Nothing beats a great piece of glass!

    I leave the digital work for the urologists and proctologists.

  6. #16
    RalphLambrecht's Avatar
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    Quote Originally Posted by ic-racer View Post
    ...Also, from what I remember, all the Leica M lenses had way more contrast, and usually better sharpness when compared to the others.
    That's good, because sharpness and contrast are far more important than resolution in my opinion.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  7. #17

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    Quote Originally Posted by ic-racer View Post
    All theoretical thinking aside, actual tests of popular 35mm lenses were conducted by Modern Photography magazine in the 70s. I have many of the magazines and there is a lot of data there. One of these days I should compile it all into a nice table like the one that is out there for large format lenses.

    I can summarize my years of reading the test reports in that most all the 'name brand' 35mm SLR lenses performed about the same at f8.

    When wide open, the results were all over the place, though, now days, a 'bad' wide open performance may actually be sought for its aesthetic qualities.

    Also, from what I remember, all the Leica M lenses had way more contrast, and usually better sharpness when compared to the others.
    In the 1970s either Modern Photography or Popular photography published an article on reaching the magic 100 lines/mm figure on Panatomic X film. There were a number of lenses which, in combination with the film, either reached or came very close to the 100 lines/mm figure.

  8. #18
    kauffman v36's Avatar
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    alan, you bring up something i was going to ask. thoeretically, what would be the combination to give the highest resolution using a 35mm system.

    im wondering if technical pan + some crazy leica or zeiss lens and a schneider APO enlarging lens would give noticably higher ln/mm

  9. #19

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    Resolution for 35mm lenses

    Older lenses have in fact been tested with document films. I experimented with 5069 for continuous tone work in High School and also used the H&W film (Agfa) and developer combinations. There is no question that these films, with the right lenses, allowed a great deal of enlargement and gave very fine grain. What they could not do is replace general purpose films for general purpose uses. What's interesting about document films for 35mm use is that they allow all of the flexibility of the 35mm format. If I just wanted an 8X10 of a static subject I could use ACROS or Pan F+ in a 6X7 camera and get more consistent results. When Modern Photograpy used Panatomic-X for tests, the negatives were examined under an Olympus Vanox microscope. If you wanted to get actual prints you still had to deal with whatever losses in sharpness would come from enlarging.

  10. #20

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    Quote Originally Posted by kauffman v36 View Post
    alan, you bring up something i was going to ask. thoeretically, what would be the combination to give the highest resolution using a 35mm system.

    im wondering if technical pan + some crazy leica or zeiss lens and a schneider APO enlarging lens would give noticably higher ln/mm
    I'm not sure which lens/film combination would come out best, but probably some film like a high contrast microfilm would be best.

    I don't recall which lenses came out with the best resolution. However, there were a number of them that were very close, and as I recall the elite brands were over represented. Don't hold me to that however.

    I have the magazine somewhere among a stack of old magazines. I re-read the article some time within the last three years, and I think it was within the last year that I read the article.

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