Viewing light

Discussion in 'Contact Printing' started by Mahler_one, Aug 21, 2012.

  1. Mahler_one

    Mahler_one Member

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    Are there any objective values provided for the intensity of the light one uses to view prints when such prints are just out of the fixer? Obviously both the intensity AND the spectrum of the viewing light can influence the final print. Hence I wonder if there are any EV or reflected light values advised for the light one uses to judge prints.

    Thanks.
     
  2. ROL

    ROL Member

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    Evaluation light only need be equivalent (intensity and qualitatively) to that used for print display. Personal experience with your own lab conditions count for a lot.
     
  3. Maris

    Maris Member

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    I use two viewing lights for assessing wet photographs just out of the fixer.

    The first light is dim and it is used to judge the tonal balance only, not detail or sharpness. The intensity of this light is adjusted way down so that wet photographs in the darkroom match dry photographs in ordinary room light. This compensates for the dry-down phenomenon. If the "tonal viewing" light is too bright all the photographs will turn out too dark when they finally dry.

    The other viewing light is very bright and is used to judge sharpness, defects, etc. It takes some mental discipline to reject the luminous beauties of a wet photograph under a bright light and accept dry-down will happen.
     
  4. Mahler_one

    Mahler_one Member

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    Yes, I am very much aware of the Bruce Barnbaum approach to gradually increasing the intensity of the light Maris. Thanks.

    So, do you calibrate your viewing light so as to be sure that it isn't too bright OR too dark?
     
  5. MattKing

    MattKing Subscriber

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    Ralph Lambrecht and Chris Woodhouse include a recommendation in "Way Beyond Monochrome".

    I'll try to locate it for you (I have edition 1).

    EDIT - I have it - on page 241 Ralph indicates that he uses two 100 Watt incandescent bulbs adjusted to illuminate a "viewing board" to about EV 6 at ISO 100, as neasured by an incident meter.
     
  6. David Allen

    David Allen Member

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    The best approach is not to judge prints when wet. I use an old microwave to dry my test prints and then assess them with the main darkroom strip light on, and then in the corridor which is somewhat dimmer.

    If I am printing for an exhibition in a gallery, I try to meter the average light and then set up a viewing board illuminated to similar value.

    For sales to people who are buying prints to hang on the wall, it is always best to view the prints with a 60 watt bulb placed 8 feet away as most people have somewhat dim lighting in their homes.

    Best,

    David
    www.dsallen.de
     
  7. jp80874

    jp80874 Subscriber

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    I have a sample print with full tonal range that looks good where I plan to show it, that I hang over the sink. I can’t equal the light in the darkroom where I will show the print, but the sample print helps me adjust my eyes and expectations. I have to mentally adjust for the roughly 10% dry down.

    John Powers
     
  8. Mahler_one

    Mahler_one Member

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    PERFECT! Thanks to David and jp as well.

    I have been using one of the Solux bulbs to evaluate the print. The bulb has the "correct" spectrum to evaluate a black and white print. However, since my darkroom is so small, the intensity of the light has to be decreased. I was looking for an EV value that one might use as a starting point. Good suggestions all.

    The resources at APUG and the willingness of others to help, makes being a member of the group very worth while.
     
  9. Maris

    Maris Member

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    For the record, I measured my wet photograph "tonal evaluation" light as providing 10 Lux at the fixer tray. The light over the work/display bench outside the darkroom delivers 390 Lux. The difference is enough for me to preview the effect of dry-down.

    As others point out all this careful adjustment is confounded by how the photographs are subsequently displayed. Some galleries use a dim 50 Lux of yellowish light in the mistaken belief that photographs will fade like old master drawings. The local camera club uses 850 Lux so that grain sniffers get a good look. You do your best but you can't win.