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  1. #1

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    Safe lights, when enough is enough

    I was wondering if and when too much "safe light" becomes too much? I saw a darkroom that had a safelight in it that measured 2' x 3' and illuminated everything, I would love to build one for my darkroom but want to be sure I don't sacrifice print quality for visibility

  2. #2

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    Too much is when the light will fog your paper in the time between taking it out of the box and putting it in the fixer. As long as you do a fog test to see how long it takes your safe light to fog the paper, there is no reason it can't be very bright. As long as noticeable fog doesn't occur in your normal printing time range.

    This is kind of relevant. The room at my college that we used to coat screen printing screens with emulsion had a gigantic window. Screen printing emulsions are cured by UV light, so the proper yellow film was applied to the window so little to no UV light penetrated. There was a ton of light in the room from the huge window. As long as you didn't leave your freshly coated screen out for hours at at time, the emulsion was not negatively impacted.

  3. #3
    Newt_on_Swings's Avatar
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    Your eyes adjust to dark environments in about 15 minutes. What might seem like a dim safelight may be adequate. But if you want the brightest, the Thomas duplex is probably the way to go. It's the easiest to use if you are constantly turning on regular lights to evaluate prints.

  4. #4
    cliveh's Avatar
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    Getting the balance right with the luminance level of your darkroom safelighting is quite important. I prefer my darkroom on the darker side, as it allows you to see the projected image better and as already said your eyes will adjust after a few minutes.

    “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. #5
    Mainecoonmaniac's Avatar
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    If my darkroom is too bright, I can have trouble focusing my easel.
    "Photography, like surfing, is an infinite process, a constantly evolving exploration of life."
    Aaron Chang

  6. #6

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    It's too much when you find it too bright, or it fogs your paper - whichever comes first. To see how long you have before your paper gets fogged, do a proper safelight test.

    Here are some things which may help:

    Darkroom Design
    http://www.kodak.com/global/en/profe...bs/ak3/ak3.pdf

    Safelights and Testing

    For a proper test procedure see "Testing Your Safelight Conditions" at the bottom of the main page:

    http://www.kodak.com/global/en/consu.../k4Facts.shtml

  7. #7

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    edcculus summarized things well. You need to be able to handle the sensitive materials you use without fogging them. The safelight should also not be so bright as to interfere with other darkroom operations, like focusing the enlarger. In any case, periodic tests are advisable. Size doesn't mean much. My safelight is based on a two tube 48 inch shop light, and it provides about the same illumination as a properly fitted Wratten No. 2 dark red lamp assembly. The Thomas safelight is based on a low pressure sodium arc lamp. While quite small, and quite safe, it gives out so much light that it is like working in a well lit room, and you have to shield the enlarger to focus.

  8. #8

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    I'd also like to add, depending on your setup brightness may not affect focusing etc. I have my safe light hooked to my timer. When I flip the manual switch on the timer, it turns on my enlarger light and turns off the safe light so I can see to compose and focus. Some will have just a permanent fixture and keep the safe light on all the time thought.

  9. #9

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    Many people mistakenly paint the walls of their darkroom black when in practice they should be light in color except directly behind the enlarger. This makes things easier to see with the same amount of direct exposure to emulsions. The low level of light is being used more efficiently.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  10. #10
    Rafal Lukawiecki's Avatar
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    I second Michael's point, that fogging test is by far unsatisfactory. In other words, even if your safelight does not fog paper, it is (likely) to be still unsafe, as it will cause a pre-exposure that will reduce overall contrast or make identical repeat exposures almost impossible—what you see in test strips will not match what you get from the actual print. I strongly recommend you do not test the safelight just to see if it fogs, for example using the common, yet flawed "coin test". You need to run a simple test that includes making an actual white light pre-exposure to check for impact of the safelight. The links that Michael has shared will help, especially the Kodak procedure.

    I've helped several friends get rid of their various issues, like "I can't get contrast right" etc, by doing a proper, with the pre-exposure, test.

    By the way, too bright-yet-safe is quite possible with the new forms of lighting, especially LED+filter, but it makes focusing, cropping, and dodging and burning a bit hard, unless you keep switching the safelight off and on.
    Rafal Lukawiecki
    See rafal.net | Read rafal.net/articles

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