Exposure calculation for colour film

Discussion in 'Exposure Discussion' started by Mark_S, Aug 21, 2013.

  1. Mark_S

    Mark_S Member

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    I shoot mostly B&W large format, using a modified zone system approach. I would like to start playing with colour, in a hybrid flow where I will shoot the colour film and process it, then have the images scanned, and I will print digitally. Many years ago I shot a fair amount of transparancy film in 35mm (mostly Kodachrome, and some E-6), and relied on the meter in the camera to determine my exposures, and was generally pretty happy with the results. I am now trying to figure out how to calculate exposures when using colour sheet films, and my primary meter is a spotmeter. - My thoughts:

    On transparancy film, it seems like the biggest issue is blowing out the highlights, so would it make sense to meter the highlights, and to place those in Zone VIII? I have a box of Velvia 100 which I will be playing with.

    For Colour negative film (here I will be playing with Ektar 100), I assume that I treat it like B&W, and meter the shadows, then place those in zone II? I think that this film has a much broader range, so I don't have to worry as much about the highlights?
     
  2. Mainecoonmaniac

    Mainecoonmaniac Subscriber

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    APUGers that know more than I, please correct me if I'm wrong. When I shoot chromes, I place in Zone VII for texture. As for color neg film, I think density is created with dye instead of clumps of silver, so it's easier to bring highlights back. If you print your own, you can burn a bit. One issue you might face is color shift on the print. If you scan your color negs, you can do an HDR version of a scan by doing one scan for shadows and one for highlights. If you highlights are blown out in your chromes, there's nothing you can do to retrieve the highlights.
     
  3. BrianShaw

    BrianShaw Member

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    Similar is true for the shadows. For chromes I find it important to assess the range of the image and if it exceeds the capabilit of the film deide which is more important - highlights or shadows.

    In fact, that is what I do for almost every type of media unless I already know (guess) the range is compatabile... then I just meter for "average" either general-coverage reflected or incident.
     
  4. Bob Carnie

    Bob Carnie Subscriber

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    I would open up a bit more for colour neg than I would for chrome.
     
  5. DREW WILEY

    DREW WILEY Member

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    I would start your experimentation at the formal midtone value (Gray card 18% or Zone V), using published box speed. Not all color neg films
    are the same by any means. For example, Portra 160 might get you something down in Zone II, but Ektar probably won't. If you do have to guess, it's better to make an error toward overexposure, provided you do so conservatively. You also have to be aware of color balance issues
    in color neg film for nonstandard lighting, which can depress one particular component dye in an imbalanced manner, making it impossible to
    correctly reproduce relative to the others. In other words, use filters to correct for significant deviance in Kelvin temp from standard daylight
    (like excessively blue shadow conditions). Some color neg films, esp those designed for amateur use, have quite a bit of latitude. But something like Ektar requires just as much care as when exposing a transparency, yet with maybe a stop more range each direction.
     
  6. markbarendt

    markbarendt Subscriber

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    Pegging to the highlights is good for transparencies, as is pegging to the mid-tones. Practice with a few sheets.
     
  7. Photo Engineer

    Photo Engineer Subscriber

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    For color neg film, forget the zone system. Just meter the scene for box speed and then overexpose by 1/3 stop. Therefore a 400 speed film would be shot at 320. There is so much latitude in color neg, that is your best bet.

    PE
     
  8. DREW WILEY

    DREW WILEY Member

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    I too always felt that the Zone System was a fish out of water when it comes to color film.
     
  9. markbarendt

    markbarendt Subscriber

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    I have learned much from the zone system and I would not understand near as much about photography without the zone system, but one of the things shooting color negatives has taught me, is that the zone system is a special case system.

    My B&W process, from camera to print has become much more like PE suggests.

    I shoot at box speed, I avoid underexposure, and like C-41 films, I develop almost all of my film to a normal standard. It has become truly rare for me to use plus or minus development.