Do I multiply or add filter factors? Using a color temp meter indoors?.

Discussion in 'Color: Film, Paper, and Chemistry' started by Puma, Jul 6, 2011.

  1. Puma

    Puma Member

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    Hello,

    Let's say I have a mired value of ten and I have a six and three filter to get me there. With a filter factor of 1.2 and 1.4 do I ADD or MULTIPLY the factors to get proper exposure?

    When using a two color meter indoors (Gossen Profi color on an Ultra Pro) Where exactly do I point it? Directly at the light source? Person's face? Supposing there's natural light behind the subject from a window? Supposing there's natural light illuminating the subject and tungsten and Fluorescent?

    Let's say I was in a hospital and wanted to take a portrait under the fluorescent light. Can I still use a two color meter for figuring out the NON-green color cast and add an FL-D?

    Let's say I'm completely in the shade. Do I point the color meter just up into the tree, at the subjects face, or out into the light away from the subject.

    The manual for using the Profi color doesn't really help with where to aim the thing in all situations.

    Thanks for your help,

    Puma
     
  2. Greg Davis

    Greg Davis Member

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    Point the incident dome toward the camera lens from the point of view of the subject, just like a light meter. Do this regardless of what kind of lighting situation you are in. You are measuring the color of the light falling on the subject as seen by the camera.

    Multiply the filter factors.

    A two color meter will not compensate for green, only red and blue. It would be better, in my opinion, to use your mired filters and add a CC20M filter for the green to get very close to correct.
     
  3. Puma

    Puma Member

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    Thank you for the information!

    By the way, I once lived in that giant building in Lexington, on the twentieth floor, (feels like) about a thousand years ago. I also took a look at your site. At first I couldn't get the "hit space" to cooperate so I thought there was nothing on there but then I figured it out. Nice work and refreshing take on large format.

    Puma
     
  4. Greg Davis

    Greg Davis Member

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    Thank you.