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  1. #11

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    Methinks me also smells some BS based on selective use of the variables. Color and b&w deliver an impression of sharpness in different manners,
    and in either case it's contrast related. Even the concept of sharpness versus acutance can turn this game into nonsense if you are merely
    crunching numbers. How you develop and print the film if a significant factor too. But overall, comparing apples to oranges is a waste of time.

  2. #12
    MattKing's Avatar
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    Quote Originally Posted by didjiman View Post
    When I shoot films, I have been mainly shooting B&W and slides. I shoot mainly in XPan, 120 and 4x5 format. Haven't shot straight 35mm for probably 8 years.

    I have a Jobo and rotary process all my films. I then scan using a LS-9000 (XPan or 6x7) or V700 (617 or 4x5)

    Last few months, I tried color films, the XPan and 120 seem not to as sharp as the slides and B&W. The negs look pretty good exposure wise, and I am precise with water temperature and timing. I use a Kodal color thermometer and not the Jobo builtin temperature gauge. For testing purpose, I even have a lab processed one of the rolls and the results are similar.

    So are color films (Portra 400) inherently less sharp than slide film or may be I am comparing apples to oranges or my process still need more tweaking?

    I use the Arista C41 for color films, divided Pyrocat for B&W, and Tetenal E-6 for slides.

    Thanks!
    Contrast is one of the components of perceived sharpness. With colour, perceived sharpness may be affected subjectively by the level of colour saturation.

    The Portra films are designed to be excellent for skin tones. They exhibit moderate contrast and saturation. So they exhibit lower perceived sharpness unless you adjust them for higher contrast and saturation.
    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
    Nikanon's Avatar
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    Quote Originally Posted by DREW WILEY View Post
    Methinks me also smells some BS based on selective use of the variables. Color and b&w deliver an impression of sharpness in different manners,
    and in either case it's contrast related. Even the concept of sharpness versus acutance can turn this game into nonsense if you are merely
    crunching numbers. How you develop and print the film if a significant factor too. But overall, comparing apples to oranges is a waste of time.

    It's not bullshit. I am aware of the other factors and that the idea of sharpnes is a subjective one to begin with. Those numbers are a useful means to understanding why color slides or negatives may appear to have less resolved detail than black and white films. I used to shoot Kodachrome long ago and was disappointed when I scanned them a couple years ago on an Imacon scanner and found their resolved details were
    No match for most of my Black and white negatives. There is something to the fact that light has to travel to three layers, not counting the filter layer in color film. The MTF is useful for understanding the maximum capabilities of a film like we may know a digital cameras resolution, of course the lens resolving on that film determines how much can be revealed. There is no number crunching at all, just simple comparing of numbers to try to understand some of the different properties.

    Acutance of the film during processing is different than the actual resolved detail as it can alter the contrast between resolved details and the perception of sharpness can be very high. If the details are not recorded however, no amount of processing can create them, which is why I mentioned this problem of resolution/sharpness arises mostly from printing very large or scanning very high resolution and realizing the film doesn't have incredible detail after a certain size. Of course you don't take the numbers to heart and say "well crap, I'll never shoot color again now" because that's just stupid.

  4. #14
    Nikanon's Avatar
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    Quote Originally Posted by pentaxuser View Post
    I may have misunderstood the science here(quite likely) but the source you quote seems to suggest that P3200 has a resolution the same as TMax400 and is better than the colour film you give as an example.

    I am particularly surprised that P3200 matches Tmax400 and beats I think it was Portra you mention

    Good as P3200 is for a fast film my limited experience with it suggests to me that even at a 5x7 size print a P3200 neg doesn't match a TMax 400 neg

    What's others' experience of this?

    pentaxuser
    All the numbers say is that under the specified conditions, the film can resolve up to this amount of detail at this percentage of contrast. The maximum a film can resolve is at a very low contrast at the end of the curve. Likely P3200 using the developer stated is able to resolve what it can because at around 70 Lp/mm the perceived contrast Is still high enough likely due to the large grain size but the finer the recorded details go the grains become too large to differentiate anymore. T-Max 400 may not be as grainy but may have reduced ability to resolve more than P3200 due to its heavy use of tabular grain and dye.

    I am not saying this is why, I am just trying to reason this out. The fact exists that this film did record this detail under the set conditions although it likely wont record that much if used normally in a real world situation.

  5. #15
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    Nikanon first I think we are comparing apples to oranges. Color and black-and-white films present their detail differently.

    Second comparing scans introduces way too many variables to allow any meaningful conclusions outside of your house or mine.
    Mark Barendt, Ignacio, CO

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  6. #16
    Nikanon's Avatar
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    Quote Originally Posted by markbarendt View Post
    Nikanon first I think we are comparing apples to oranges. Color and black-and-white films present their detail differently.

    Second comparing scans introduces way too many variables to allow any meaningful conclusions outside of your house or mine.
    Fair enough, I don't work with color enough anyway to really examine the theory I am describing.

    I guess I am just saying that I miss Kodachrome 64 :-/

  7. #17

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    Of course it's BS. Throw away your calculator and actually print all these film for forty years like I have! The graphs are useful, but only when
    the playing field is perfectly level; and the whole name of the game in the darkroom is to skew the variables. A particular black and white neg
    which might appear sharper in a 16x20 print versus its color counterpart might see the apparent result switched in a 30x40 magnification, for
    example. There are all kinds of ways of tweaking these things, and I'm not referring to digital manipulation. Sometimes a grainier film appears
    sharper than a fine-grained one, sometimes it doesn't. It can even depend on which dye layer of a color film is predominantly exposed. We could talk for hours and hours about this. Those of us who cut our teeth on Kodachrome 25 thought the 64 version stunk. It's all relative.
    But if detail is a priority in color, take a look at Ektar. Otherwise, shoot a larger format (I do both).

  8. #18
    Nikanon's Avatar
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    You are right in the practical applications, but its still not bullshit. The facts are what they are and knowing them can be useful, although it isn't necessary as many successful photographers can attest to. The science and math is supplementary, but shouldn't restrict the way that you work. When im out photographing, im not thinking of all that nonsense, and quite often im not when im printing or developing either, its just useful to understand the process and how your materials function in order to deconstruct the mysteries of it at times.

  9. #19

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    Thanks for all the comments. I was hoping someone else who uses all 3 types of the films can make some generalized statements, but I will just chalk it up as apples vs. oranges.

  10. #20

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    There are not only whole different categories of film, but within each of these different categories many different specific products, each with
    more than one way of using them. A color neg film primarily marketed for portrait use, like Portra 160, will be engineered with fine grain but
    low contrast. That can be altered to some extent by how you print it; but it behaves differently than something like Ektar, which has been
    engineered for a different range of potential applications, even though it belongs to the same general family by the same manufacturer. You
    can take a black and white film like HP5, develop it in pyro, and it will look like utter mush under a high-powered loupe, if you compare it to
    TMax 100. But when you print both of them at, say a 5X magnification, the HP5 will actually seem crisper or apparently sharper. Change the
    developer or make significantly greater scale enlargement, the effect will be different. There are just way way too many variables to make
    crude generalizations.

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