RA4 printing

Discussion in 'Color: Film, Paper, and Chemistry' started by AMBYSTOMA, Aug 27, 2011.

  1. AMBYSTOMA

    AMBYSTOMA Member

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    To obtain a proper color balance forget about using subjective techniques, such as looking thru filters. On every roll of film shot (or when using a different emulsion or lighting conditions) shoot a photo of a gray card. Make a print of the grey card; use must have a reflection densitometer to read the grey card. Measure the cyan, magenta and yellow- perfect color balance is obtained when you get 0.8/0.8/0.80 for the c/m/y. This is an infallible objective technique, which I have been using for many years. Incidentally, I use an X-Rite 404 reflection densitometer.
     
  2. pentaxuser

    pentaxuser Subscriber

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    Can you explain to someone who hasn't got a reflection densitometer how you take measurements of the grey card frame to result in 0.8 for all three colours and how this is turned into the correct filtration values.

    Thanks

    pentaxuser
     
  3. Photo Engineer

    Photo Engineer Subscriber

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    Unfortunately a single point measurement does not always work.

    PE
     
  4. AMBYSTOMA

    AMBYSTOMA Member

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    the test print containing the grey card is read by the densitometer and the filters in the dichroic head are adjusting according to the grey card reading; i.e., cyan, magenta and yellow are added or removed until approximately equal amounts of these three colors (0.8, 0.8, 0.8 ) is obtained on the test print.
     
  5. markbarendt

    markbarendt Subscriber

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    There are also the Beseler color meters that "read" the light directly from the enlarger, once baseline testing for a given paper is done this eliminates the need for a test print where a known color can be measured.
     
  6. Photo Engineer

    Photo Engineer Subscriber

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    Color papers rarely have matched densities at 0.8. They are usually just slightly magenta / red to make flesh tones more appealing as pictures of people represent the largest family of prints. Also, wedding gown white is at that point and brides prefer white to off white (pink direction) rather than green.

    So, balancing gray in this fashion can often lead to off color mid to denser areas. It is best to judge the overall print rather than just one spot.

    PE
     
  7. ghostcount

    ghostcount Member

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    Hail to the nonlinearities in analog photography.
     
  8. markbarendt

    markbarendt Subscriber

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    I do agree that overall color should be judged.

    That said the primary color I key to with my Beseler is my own skin tone in a reference shot with my meter. Thats normally enough but having the meter in the shot gives me a known black, white, and grey target to check too.