Color film less sharp than slides / B&W?

Discussion in 'Color: Film, Paper, and Chemistry' started by Richard Man, Oct 3, 2013.

  1. Richard Man

    Richard Man Member

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    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!
     
  2. Nikanon

    Nikanon Member

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    Most likely it is your scanner on the 120 issue with how it is mounted. Your film really has to be dead flat to scan well, and 120 is a larger surface area and therefore has a better chance of not being totally planar during the scan. I warm up my negatives and then stick them under a book or other totally flat surface with weight for a whole day.

    Color films are however actually less sharp than their black and white counterparts. The line pair resolution of color films is much less, likely due to their being made up of coupled dyes and the orange mask that is placed over negative films.

    Color negative and positive films are pretty similar in their characteristics of resolution, but it really depends on which film you are talking about.

    Remember, "sharpness" is meant to be the perceived contrast of edges of fine details throughout the image. Monochromatic silver grains can render higher resolutions than multicolored dye any day.
     
  3. markbarendt

    markbarendt Subscriber

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    Got data to back that up?
     
  4. thegman

    thegman Member

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    In terms of line pairs per mm, it's not possible to say 'black and white is more than colour' any more than you can say 'Canon DSLRs have higher resolution than Nikon', you'd really have to come up with some specific examples.
     
  5. Nikanon

    Nikanon Member

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    Here is the PDF for Ektachrome 100, but any Data sheet that gives MTF will tell the same story. The Lp/mm here is about 30 at 50% contrast:
    http://www.kodak.com/global/en/professional/support/techPubs/e113/e113.pdf

    Here's the Data sheet for portra 400, where the MTF 50 of the longest wavelength red, is also about 30-40 Lp/mm:http://www.kodak.com/global/en/professional/support/techPubs/e4050/e4050.pdf

    Here's Kodak Tri-x 400, a fairly lower resolution film among black and white films, it can still resolve about 50lp/mm at MTF 50: http://www.kodak.com/global/en/professional/support/techPubs/f4017/f4017.pdf

    Of course there are other factors such as development and what lens you ate using, but otherwise resolution is essentially a measure of perceived sharpness at MTF50.

    Don't expect the same fine details from even Kodachrome 64 slides as from say, Ilford FP4.

    The image size will also affect perceived sharpness as the eye (or your computer screen) can only resolve so many line pairs at a specified distance. At a small enough size the same lens imaging on color and black and white films the same scene, the images will look indistinguishable in their "sharpness".

    T-Max 400 resolves about 75 Lp/mm, while t-max
    100 resolves about 120, and even the grainy P3200 can resolve about 75 Lp/mm at MTF 50: http://www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.pdf
     
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  6. polyglot

    polyglot Member

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    As an overgeneralisation, yes it is true that most C41 films are softer than (some) B&W films and chromes.

    Practically nothing is less grainy than Acros or TMX, and nothing in ISO400 is as good as TMY2, so there's that. But then, nothing is coarser at a given ISO than Fomapan, so it depends which films you are comparing.

    In my experience, Ektar is about as sharp and smooth as Velvia, maybe even better and RVP50 is the smoothest reversal film on the market, so the "best" C41 is smoother than the smoothest chrome. But then, the cheaper (Reala) and older (400VC) C41 films are very coarse compared to chromes of similar vintage (RDP, RXP), whereas the newer CN emulsions (New Portra in 160 and 400) are very fine. P400 is better than Reala and RXP but can't match RDP. P160 is probably as good as RDP.

    So you can cut it whichever way you like really. Quantitative comparisons are also very difficult because MTF50 on the film means an entirely different thing on a negative as a positive because of the contrast gain in the printing process. A C41 neg that will achieve the same MTF50 in a print will have a lower MTF50 in the negative, which means comparing it to the MTF off a chrome is unreasonable. But then, chromes can have a higher Dmax, which means they naturally have the opportunity to get better acutance than any reflected print can achieve.

    Just shoot what you like. If you want to try a colour neg that looks like a chrome, get some Ektar and print it optically. Hint: Ektar is comparatively cheap in 4x5" :wink:
     
  7. Nikanon

    Nikanon Member

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    Knowing resolution and how it affects the image can be useful, but for shooting 35mm negatives or slides, or even 120, I would imagine its more about the color. There's less you can do to control "sharpness" anyway with your color films. If
    You want fine details, larger format, if you want relatively small prints, 35mm should be fine.
     
  8. Prest_400

    Prest_400 Member

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    I am in the process of printing (hybrid) some 35mm slides (KR64 and Fuji Sensia). On screen the scans differ a lot in color (I prefer much more film) compared to digital (which I use in a more careless way, BTW; Only JPG). For me a 8x12" print is quite big at the moment and medium speed film should fulfill nicely. Some grain doesn't hurt and it can help in acutance.
    Slide needs a careful approach to (hybrid) printing, as I found it loses "crunch" (transmittive to reflective media).

    I've gotten some Portra 400 to try and want to get a bit of ektar for next spring. As of products, Portra 400 has lots of praise for what it delivers, being ISO 400. I wouldn't be surprised if it's grain wise on par or slightly grainier than Kodachrome 64, at 8x12".
     
  9. pentaxuser

    pentaxuser Subscriber

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    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
     
  10. polyglot

    polyglot Member

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    It's why you don't compare numbers from separate sources, because there are so many differing ways of defining the measurements. Note also that resolution and graininess are not that well-correlated.
     
  11. DREW WILEY

    DREW WILEY Member

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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.
     
  12. MattKing

    MattKing Subscriber

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    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.
     
  13. Nikanon

    Nikanon Member

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    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.
     
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  15. Nikanon

    Nikanon Member

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    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.
     
  16. markbarendt

    markbarendt Subscriber

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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.
     
  17. Nikanon

    Nikanon Member

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    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 :-/
     
  18. DREW WILEY

    DREW WILEY Member

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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).
     
  19. Nikanon

    Nikanon Member

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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.
     
  20. Richard Man

    Richard Man Member

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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.
     
  21. DREW WILEY

    DREW WILEY Member

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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.
     
  22. Richard Man

    Richard Man Member

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    The thing that got me on this is that I have shot rolls of Provia / Sensia 35mm XPan (35x66) format in the late 2000s in Japan / HK. I processed those rolls myself and I have 6 4+ feet long canvas prints hanging on my wall right now that I look at everyday. They are canvas prints so obviously we are talking about prints with texture. In any case, while I have not printed huge yet with the color films, but I just do not think the 35mm Portra 160/400 from the same camera/lens have that type of ... visual impact. The 120 and 4x5 of course do, but lets just say I am not happy with the 35mm color film and I want to know whether it's something I can tweak or I should "give up" on that process.
     
  23. jnanian

    jnanian Advertiser Advertiser

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    so many technical conversations just boil down to subjectivecrap ..

    do what you want and enjoy what you do. ...
     
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  24. Dr Croubie

    Dr Croubie Member

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    It's always going to be apples and oranges between B+W and Colour, just because of how our eyes work, for a good rundown read this. The bit down the bottom about Monet is especially interesting, years before colour photography and computers.

    But between negs and slides, no idea. I've just been scanning a very-expired Gold 400 shot on my 1/2-frame Agat 18k. Having no lightmeter, and very expired film, a lot of them were underexposed. Those had massive grain even viewing on-screen at 4x6 print-size. Others were perfectly exposed and the results looked good enough at about 8x10" print-size.
    In lab conditions, with a certain MTF/% definition of 'sharp', maybe Velvia beats most negs. Maybe Ektar even beats Velvia. but go out in the real world and shoot something else, and the results might be different. (wow, i think I've heard exactly the same thing on gear-head forums about the D800e vs D800 vs 5D3 and Zeiss lenses vs Canon's L)
     
  25. markbarendt

    markbarendt Subscriber

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    the only way you are going to figure this out is to actually try.
     
  26. Richard Man

    Richard Man Member

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    I *am* trying, but doesn't hurt to ask people if they have actual experience. It's not like I just shot one roll each and complain *roll eyes*

    Thanks for the helpful advices from those of you who actually gave such.

    // should add that this is not directed at you markbarendt, but to the others.
     
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