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  1. #31
    AgX
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    As said, make a check with a UV-lamp before buying. A simple miniature UV-TL tube as used for bank-note checking will be sufficient.
    In case you should not know what to expect, just get into a darkened room with some common papers around, then you'll know what to look for at the paint dealer.

  2. #32
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    As others have pointed out optical brighteners in paint are not a problem in a darkroom. As Steve mentioned it's the colour that white reflects.

    “The contemplation of things as they are, without error or confusion, without substitution or imposture, is in itself a nobler thing than a whole harvest of invention”

    Francis Bacon

  3. #33
    AgX
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    Not quite true, it's about the colour that the wall reflects and emits.

    In case you have not much UV-light, there will not be much blue emittance either.
    But many darkrooms are used for lighted work too, as critical proof of prints, including colour prints. What would be the idea behind installing a high quality daylight-TL lighting when you add additional blue to the room, and the print to be examined.

    Maybe this all is academic. But so might be this whole thread.

  4. #34
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    Quote Originally Posted by AgX View Post
    Not quite true, it's about the colour that the wall reflects and emits.

    In case you have not much UV-light, there will not be much blue emittance either.
    But many darkrooms are used for lighted work too, as critical proof of prints, including colour prints. What would be the idea behind installing a high quality daylight-TL lighting when you add additional blue to the room, and the print to be examined.

    Maybe this all is academic. But so might be this whole thread.
    You may be correct, as I have never compared densitometry readings of prints produced in darkrooms painted with normal white paint and those painted with white containing optical brighteners. However, this is not at the top of my photographic priority list.

    “The contemplation of things as they are, without error or confusion, without substitution or imposture, is in itself a nobler thing than a whole harvest of invention”

    Francis Bacon

  5. #35

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    There are no "optical brighteners" in architectural wall paint, merely different qualities of white support pigment: titanium dioxide at the high end of reflectance, calcium carbonate in the middle, silica at the cheapie end, and more often, some kind of blend of these. None of them fluoresce. But the brighter the paint, the more any surrounding light contamination will get bounced around. And I really don't care who says what. You might get away with certain compromises making ordinary prints, but if you develop a relatively high-speed film in trays, you might get stung in the shadow values.

  6. #36

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    I painted my walls clear so I wouldn't have to worry about this!

    Jeff
    Last edited by Jeff Kubach; 01-21-2013 at 06:30 PM. Click to view previous post history.

  7. #37

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    Quote Originally Posted by JBrunner View Post
    My darkroom is red. ......
    Seriously, would this not be the most efficient option? I've been using a red LED safelight bulb, with a pretty bandwidth of light.
    My darkroom needs a good coat of paint, and I was considering going grey, as in the 18% greycard, in order to neutralize reflections but, if I went with full red, I should get close to 100% reflectance of the good (safe) light while reducing reflectance of unsafe wavelengths down to a minimum. All this assuming that I'm concentrating on B&W work. Any thoughts?

  8. #38

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    Quote Originally Posted by barzune View Post
    Seriously, would this not be the most efficient option? I've been using a red LED safelight bulb, with a pretty bandwidth of light.
    My darkroom needs a good coat of paint, and I was considering going grey, as in the 18% greycard, in order to neutralize reflections but, if I went with full red, I should get close to 100% reflectance of the good (safe) light while reducing reflectance of unsafe wavelengths down to a minimum. All this assuming that I'm concentrating on B&W work. Any thoughts?
    But when you turn the white room lights on, everything will look red. I want to see my prints as black and white, not black and pink! I also think grey would be pretty gloomy under both safe and white lights.

  9. #39
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    For the same reason the inside of all cameras (that I have ever seen) are flat black, this would be my first choice. It would be easier, in my opinion, to add safelight light where needed, and not have to deal with stray light, than trying to reduce bounced or reflected light where not wanted. Viewing light also is easy to add.

    If it is a dual purpose room, then the other use would rule this out. JMHO
    Items for sale or trade at www.Camera35.com

  10. #40

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    Barzune
    You are absolutly correct. and if you hold prints in plain view of a white light the black and white print will reflect white light. Our brains accomadate any minor reflectance from walls. Whether you like the room colour when the white lights are on is up to you.
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

    Regards
    Bill

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