Exposure compensation for B&W for tungsten lighting.

Discussion in 'Exposure Discussion' started by JBrunner, Feb 9, 2006.

  1. JBrunner

    JBrunner Moderator Staff Member Moderator

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    I have managed to convince a client to shoot 4x5 b&w for a job instead of digital. (Yeah!!!!) The location dictates I use tungsten (approx 2900K) Are any exposure adjustments needed for spectral sensitivity? The film I have on hand is Efke PL 100 (probably too slow, as I have a human subject)
    J&C 200 & 400, and Tmax 400.
     
  2. Nick Zentena

    Nick Zentena Member

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    Going to depend on the film I bet. I sort of remember Forte gaining speed while most films lose speed.
     
  3. Ole

    Ole Moderator Staff Member Moderator

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    All I can remember is that Forte 100 and Ilford FP4+ will gain a little speed, most others will hold speed or lose a little, except EFKE 25 and 50 which will lose a lot.
     
  4. Kirk Keyes

    Kirk Keyes Member

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    It also depends on your meter's sensitivity to infrared light.

    Kirk - www.keyesphoto.com
     
  5. JBrunner

    JBrunner Moderator Staff Member Moderator

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    Love your work Kirk.

    What would my meter's infrared sensitivity have to do with it?
     
  6. df cardwell

    df cardwell Subscriber

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    despite manufacturers, charts, and all branches of science, give at least an extra half stop

    i'd go with TMY, and just give a little extra exposure... it's long straight line means extra exposure doesn't alter contrast


    and, of course, test ahead
     
  7. Kirk Keyes

    Kirk Keyes Member

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    Thanks for the comments on my photos!

    All meters react to different colors differently. Simplistically, you can think of the meter being reactive to 5 light ranges - the 3 you are probably used to thinking about - red, green, and blue. But then it will also have some sensitivity to ultraviolet and infrared.

    The warmer the tungsten light, the more IR there is in the light (and the less blue and green there is, and almost no UV). If your meter is sensitive to the IR, then the warmer the light source, the more the IR will affect the meter. It will give higher readings than if the meter is not as sensitive to IR.

    It's the same kind of issue as the film's spectral response.

    Kirk
     
  8. Joefoto

    Joefoto Member

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    For tonal range, I'd go with the Efke, and avoid the TMY all together (JMO). Congratulations on convincing someone that film is better than digital any day! Especially shooting 4x5.

    I used to shoot HP5+ for portraits, and this may work for you....there's something about the way Ilford downplays skin blemishes. I used TMY on Maui for a portrait shoot, and the results were awful (client brought it to me). Good thing I'd loaded HP5+ as a safety in the opposite side of the holder.

    Just my $0.02, best of luck.

    Rolleijoe
     
  9. JBrunner

    JBrunner Moderator Staff Member Moderator

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    Update

    Well, its a done deal and I'm looking at good negs. I decided to purchase some TriX and go with that. Shot a couple for the meter and the rest one stop over. Processed in Pyrocat. They are all in scan range, however the 1 stop over would print better.

    Thanks everyone for your advise. The conclusion is that a one stop over exposure is appropriate for TriX under tungsten. On the meter sensitivity note, I took all my meters (5 incident and two spot) and they all agreed within 1/3 stop. (which is all they ever do)

    Thanks everyone for your advise.
    Chalk one up for the film freaks!