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  1. #11
    Diapositivo's Avatar
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    The question you raise can be generalized in how many pixels a film camera, with high quality optics and high resolution film, would have if compared with a modern digital camera. It is an interesting question indeed for the technically minded.

    I'll jump very quickly over all the obvious stuff about the fact that resolution does not art make and post here some interesting observations that somebody else made on the subject.

    Norman Koren has an extensive essay:
    http://www.normankoren.com/Tutorials/MTF7.html

    Ken Rockwell makes some interesting considerations:
    http://www.kenrockwell.com/tech/filmdig.htm

    Another simplified text quoting Ken Rockwell:
    http://wiki.answers.com/Q/How_many_m...aximum_quality

    I find this text by Vitale to be extremely interesting:
    http://cool.conservation-us.org/cool...resolution.pdf

    I would like to add two personal considerations:

    My slides scanned at 4000 dpi with a Nikon Coolscan 5000 ED yield scan files of around 108 MB 16 bit per channel. That equates to 54 MB at 8 bit per channel which corresponds if I get it right to a JPEG obtained with a 18 megapixels camera. I see no "wasted pixels" on my scans. When I view images along diagonal edges at 600% or so on the monitor, so that I can see each scanned pixel as a square on the monitor, I can clearly see no "double pixels", each pixel is different from the ones near to it and they all contribute to the image. I see that each pixel is useful to the definition, there are not pixels which do not contribute to the definition of the image, so my personal take is that 100 modern high-resolution slide film like Astia 100 is certainly capable of deliverying a resolution comparable to a 18mp camera. That's comparing digital to scan, which puts scan at a disadvantage (nobody tried to compare digital and film the other way, by obtaining a slide from a digital image, and comparing it with a film slide).

    On the other hand, stock agencies like Photolibrary which would not accept images below 12 mp go on accepting scanned 35mm images, not necessarily drum scanned. That poses film scans above the 10 mp league.

    So I think the equivalent resolution of film, by my impression and judging by industry practice, is more or less in the 15 - 20 mp range.

    Fabrizio
    Fabrizio Ruggeri fine art photography site: http://fabrizio-ruggeri.artistwebsites.com
    Stock images at Imagebroker: http://www.imagebroker.com/#/search/ib_fbr

  2. #12
    MattKing's Avatar
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    Questions like the ones raised here are only meaningful when considering prints. Given how undemanding even the highest resolution monitors are, it seems ironic that the questions are even asked when you consider how (relatively) few digital files ever end up getting printed.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  3. #13

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    About eyesight resolution, I found in several astronomy books (concerned with optical instruments) that it went down to 3/4 of one minute arc (one minute arc is 1/60 of a degree) so approximately 1/80 of a degree. This is meant to be the "grain" of the human retina at the spot called the "fovea" - and which is considered to be relatively constant from one person to another, and gives the limit of the best sighting when our eyes are optimally focused.

    Paul
    Last edited by polka; 12-29-2010 at 04:04 PM. Click to view previous post history.

  4. #14
    T42
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    Hello Folks.

    @Fabrizio
    Thanks for your experience based insight and for those links. That was very useful reading.

    @Matt
    Good point. I guess I am just a curious person wanting to get a grasp on "how good" the early cameras were which made those first 35mm pictures in LOOK, LIFE, and National Geographic. I suspect that they would not translate into much in terms of megapixel equivalence, but it's just a guess.

    @Paul
    That's very good data which I had not heard about. 1/80th of one degree. The authors of the Leica Manual of 1956 say it's 1/30th of a degree. And they conclude that most folks can only resolve about 100 lines per inch (25.4mm) when viewing a print at ten inches (254mm). 1/80th of a degree seems to turn that idea on its head. I'm assuming that the "lines" in the 1956 Leica Manual are equivalent to today's "line pairs," since the "lines" described had bands of white space between each of them.

    Thanks again for the help.
    Henry
    A Certified Dinosaur
    Nikons F, F2, D700, Leica M3, & Kiev 4a

  5. #15
    Erik Petersson's Avatar
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    It would be interesting to know how such maximum eyesight translates to the opticians recommendations. In Sweden - and probably elsewhere - they strive for 1.0 eyesight when adjusting eyeglasses. It means that one can resolve the smallest line of letters on that traditional poster on the wall. 0.9 or 0.6 means that one can resolve the next smallest or the sixths smallest line.

    Myself, I can see none of those letters without glasses or contact lenses, but with them I exceed the recommendations considerably (1.5 eyesight they told me.)

  6. #16
    Jim Jones's Avatar
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    Quote Originally Posted by polka View Post
    About eyesight resolution, I found in several astronomy books (concerned with optical instruments) that it went down to 3/4 of one minute arc (one minute arc is 1/60 of a degree) so approximately 1/80 of a degree. . . . .
    The eye constantly moves, and perhaps superimposes image upon image much as video does. If large projections of grainy movies appear reasonable sharp, perhaps our eye and brain accomplishes the same. Just a thought, with no scientific citations to support it.

  7. #17
    AgX
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    That's very good data which I had not heard about. 1/80th of one degree. The authors of the Leica Manual of 1956 say it's 1/30th of a degree. And they conclude that most folks can only resolve about 100 lines per inch (25.4mm) when viewing a print at ten inches (254mm). 1/80th of a degree seems to turn that idea on its head.
    At my age all these numbers have merely academic value...

  8. #18

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    having used a 1938 Leica I can honestly say that the quality is perfectly fine and although not as painfully sharp as a cannon 50D when scanned on an imacon you get a very fine 55meg file, I have no idea about the teccy stuff but I do know that the look of the Leica is perfectly good for most things, and has a fingerprint that is a lot more sesitive than most if not all digital captures to give you an idea of what I mean the files on this link below are all taken with a Leica II

    http://aluncrockford.com/archive2.html

  9. #19

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    just googled this which agrees with what I knew from my astronomy books : see his definition of Blackwell's "critical acuity" as the resolution of a spot as a non-point source (which is the thing that matters most to astronomers).

    ... and a lot of other very interesting related data in this document

    Paul
    Last edited by polka; 12-30-2010 at 03:31 PM. Click to view previous post history.

  10. #20
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    Seeing What the First Leica Photographers Photographed

    Your question and line of inquiry regarding the first Leicas touches on the larger issue of how we "see." For me, this is an issue of both professional and personal interest . . . I am a Leica shooter and I design visualization software. Allow me to make a couple of observations/points:

    1) "Seeing" is a largely cognitive process that involves, among other things, the subconscious reinterpretation of a two dimensional representation on our retina into a three dimensional spatial scene. "Pixel count" is merely one factor that influences how the brain/mind accomplishes this task.

    2) As another thread contributor guessed (correctly), the mind constructs the image we see by integrating a series of "perceptive passes" over the field of view and knitting them together to form what we perceive as "what we see." As the eye is sweeping a scene, it is constantly adjusting the iris (aperture) to compensate for different light levels (think HDR only biological) as well as INCLUDING and EXCLUDING items that either meet or fail to meet what is of conscious interest to the viewer. You know the phrase: "I looked right at it and just didn't see it." Indeed. Visual cognition at work. (For more info on this process, take a look at this book: http://www.amazon.com/Visual-Intelli...4156047&sr=8-1)

    3) Viewing a photograph is actually done from a perspective that is two degrees removed from objective reality (that is, what a collection of CCTV cameras might record): first, you are seeing what the photographer has chosen to capture, in the manner s/he chose, with the tools s/he had available. Lots of subjectivity and exclusion at work here. Second, you are also bringing cognitive biases to bear on your process of looking at that image. If, for instance, you are looking at one of HCB's images, you might ask: is this a decisive moment? If so, how? Or perhaps you are hyper attentive to the sexual tension that suffuses Helmet Newton's work. Either way, you are subconsciously (and maybe consciously) filtering the scene, emphasizing some elements, while de-emphasizing others. And because of that, the moment of visual cognition and apprehension is ultimately personal and unique.

    So what does this mean for the early Leica shooters? And why was their work considered "great"? The early Leica shooters were using an instrument that was the first of a new genre of photographic tool: light, portable, high quality lens, virtually indestructible. For its time, the Leica was the best of its class. And the images that were produced were, for their time, some of the best.

    Best in what way? Well, the portability of the Leica enabled photographers to take a camera where it previously could not, the quality of the lens (and their speed) enabled them to capture scenes that had eluded earlier generations of photographers, and the ruggedness of the camera enabled them to capture scenes that would have literally destroyed other instruments. Put another way, they captured life in the extreme, on the edge, in the shadows. And before the advent of the portable, small camera (e.g. Leica) that was difficult if not impossible to do.

    And pixel count? However you equate pixels to a particular film's resolving power, the fact remains that the emotive and intellectual power of these images was not compromised by either the optics or the film technology of the time. How can I be sure? We still view those old images with wonder, we still perceive the moments the photographer sought to capture, and we agree --- however much technology has advanced --- that many of those images changed how we look at the world and indeed, how we photograph our world.
    Leica MP, M7, Fujifilm GF670
    http://markgoodephotos.wordpress.com

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