Question on intentionally overexposing c-41 color film

Discussion in 'Exposure Discussion' started by carvinconcrete, Dec 21, 2013.

  1. carvinconcrete

    carvinconcrete Member

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    Hi everyone, new here!
    I have heard it is generally a good idea to rate color negative film one half to one full stop overexposed (i.e. rating 400 at 200) for better shadow detail, contrast, and color. My question is, is this only beneficial when your lab offers pull processing or is it a good idea to have slightly overexposed color negative even if your lab does not offer special processing?
    (My apologies if this has been asked before, I did search but I couldn't find an answer)
     
  2. alienmeatsack

    alienmeatsack Member

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    I think it depends on the film and its age. Some films will change colors/tones/hues a little when over and under exposed... and the push or pull processing also shifts the colors a little as well.

    I usually shoot color film that's new at box speed, only adjusting exposure based on the shot and the amount of shadow it has and hope for the best. When I use expired films or cheap films, I just shoot and enjoy the results I or the lab gets.

    The only way to really tell is to shoot a roll and do some bracketing on shots, make notes of settings, and see what you get. I find some films will vary wildly based on a stop of exposure.
     
  3. wiltw

    wiltw Subscriber

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    Color neg film has long been know for its good tolerance of overexposure. So this seems to well complement the color neg intolerance of underexpose, where the colors get 'muddy'. So, by overexposing by 1EV, one can avoid muddy color in the shadows.

    Since the labs automatically print based upon density of the neg, a more dense and slightly overexposed neg simply gets increases exposure of the paper to the negative's darker image, and all is well again.

    Shooting weddings on color neg, I routinely under-rating set my exposures, to avoid muddy colors in the shadows. ISO 160 film might be exposed to EI 100, for example
     
  4. adelorenzo

    adelorenzo Subscriber

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    You would overexpose a stop or so and process normally. No need to pull. I shoot Portra 160 at 125 and process normally, for example. That's a good suggestion to shoot a test roll and bracket some different exposures and see what works best for you.
     
  5. Photo Engineer

    Photo Engineer Subscriber

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    Generally you should only overexpose by about 1/3 stop and thus a 400 speed film would be 320. However, good results can be obtained by overexposures of 1 - 2 stops. I have posted an exposure series of Portra 160 elsewhere on APUG. It covers a full over and under exposure range.

    PE
     
  6. Poisson Du Jour

    Poisson Du Jour Member

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    An 0.3 stop over-exposure is usually, in my experience, too small and inconsequential to be noticed with the latitude of C41 emulsions, including Portra that I have used. If the question was about transparency film, over- and under-exposure would be a more critical consideration. I would not be concerned about 0.3 or even 0.5, but run a series of tests at 1.5, 2 and 3 stops up and down. Many photographers set their exposure preference based on tests in given lighting conditions e.g. flat/overcast vs bright sun with shadows, and use their standing test results to achieve the outcome based on prevailing conditions.
     
  7. Pioneer

    Pioneer Member

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    Over exposing color negative film usually helps to ensure that your shadows have some detail in them. But to be totally honest I have better luck from exposing for the shadows to start with.

    But, try it for yourself. Load your camera up with a roll of your favorite color film, shoot it at box speed. Then load the same film, shoot it one stop over exposed. Have it developed and see if you can tell any difference. I will bet that you can't. My experience is that unless you develop your own film, you won't see much difference.

    Unless you are shooting Ektar 100 of course. The do yourself a favor and get your exposure right. This film does not like under exposure.
     
  8. carvinconcrete

    carvinconcrete Member

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    Thank you all very much for clearing that up! A lot of helpful advice. I will run some tests and do some bracketing as soon as possible
     
  9. Tom1956

    Tom1956 Inactive

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    First thing is to know what kind of accuracy your shutter and your meter are giving. Without that, every exposure is presumed inaccurate. Especially the leaf shutters. I haven't found one accurate yet. You need to keep on top of them every minute. On the other hand I have a Nikkormat FT2 that has never been touched for service, and it's dead on the money. Yes that includes Hasselblad. They are way off, too. Without service, you can't say what is "1 stop overexposure". Knowing that and your meter accuracy, 1/3 over on color neg film is optimal.
     
  10. benjiboy

    benjiboy Subscriber

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    Unless I have a very good reason I always expose professional films at the box speed and rely on the film manufactures knowing the true speed of their products, unless I get consistently underexposed results, only then do I consider adjusting the I.S.O.
     
  11. Photo Engineer

    Photo Engineer Subscriber

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    That ISO fits a generic guide set up by the ANSI standard committee on photography. It does not take into account all of the real world conditions. So, a tad of adjusting is going to be needed in extremes of sunlight and etc. Slight overexposure is one way to correct that without a lot of tests.

    And yeah, we do know what we are doing. I was one of those guys doing it. I still use 320 for a 400 film!

    PE
     
  12. Pioneer

    Pioneer Member

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    That means I can credit you with that awful Kodak Ultramax 400? :pouty: :whistling: :D
     
  13. markbarendt

    markbarendt Subscriber

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    C-41 films are very flexible, consider for a moment the lighting range disposable cameras have to operate in and there is no adjustment provided to change the time or f-stop. The reason these cameras do just fine in most situations is the inherent latitude of negative films.

    The exposures that come from disposables or toy cameras may vary by 4-5 stops, say 1 under to 4 over. Surprisingly decent prints displaying normal color, contrast, and detail may be doable across that whole range. YMMV depending on lots of things but lets keep it real simple for a moment.

    Negatives normally record a much larger range of info from every scene than will actually be printed directly.

    As an analogy, think of yourself standing on the second rung of a 15' tall ladder and your hands are on say the 9th rung. The ladder represents the range negative catches, you represent the range the paper can print. As long as you (the paper) stay inside the ladder's (the negative's) range you can get essentially equal prints in terms of detail and contrast.

    In the analogy if you reduce camera exposure you, the paper, moves down the ladder and when you hit ground you start losing shadow detail. Increasing camera exposure is like moving yourself (the paper) up the ladder, at some point you reach the top of the ladder and start losing highlight detail.

    Photographers like Jose Villa claim to lean significantly toward the overexposure side, there is more to the story though. Jose's shots are typically backlit portraits. IMO he is simply giving his main subjects very full exposure so that he can print bright skin tones/mid-tones. He is willing to let the background fall where it may. The background in Jose's shots is simply a light pastel blur. It is a style choice he has made. In contrast a landscape shooter might not want to use that much exposure, detail in the clouds may be important.

    So, rather than saying one "should" give negatives extra exposure in general, I'd suggest simply that generally you should avoid underexposure until you have tested clear to the print to find your minimum and maximum exposure limits in all the various lighting situations and subjects you normally encounter.

    No push or pull is needed for any of this to work.
     
  14. Photo Engineer

    Photo Engineer Subscriber

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    I am not familiar with that product in any way. Sorry. And, it is not in the current product list. If you are right then they were smart and quit making it! :D

    PE
     
  15. Photo Engineer

    Photo Engineer Subscriber

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    As to the tonal range of color films, I have exposed Portra 160 NC and VC both from ISO 25 to 400 and gotten usable pictures.

    PE
     
  16. Tom1956

    Tom1956 Inactive

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    I've always wondered how many chemists, scientists, and engineers were on EK staff and on the premises each day. On top of that, there must have been many non-Kodak people actually on the premises also each day, from defense contractors and commercial consumption each day. With that wonderment I speculate that if you were somebody not smart enough to cut the mustard, you didn't last at EK very long. I suppose I've always wondered these things as I perused the products in the camera stores as a young person in the 70's.
     
  17. Photo Engineer

    Photo Engineer Subscriber

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    In my time there, KRL had about 2000 people doing R&D in Rochester with 120,000 world wide in overall operations and about 60,000 of them in Rochester. There ere 3 R&D facilities. One here in Roch. one at Harrow England and one at Chalon France.

    There was a regular staff and a senior staff for "professional employees" and a "technician staff" for others. We were paired 1 professional heading a Lab with about 20 - 30 in the lab. Each professional staff in the lab had 1 - 3 technicians under them to do work. R&D on a product took up to 5 years. We used a staff of up to 6 professionals and their associated technicians on each product. Support staff included the coating engineers that mad coatings and process engineers that processed them if we did not do it ourselves.

    There ya go Tom.

    PE