Safelights, how safe?

Discussion in 'Darkroom Equipment' started by Theo43, Oct 23, 2009.

  1. Theo43

    Theo43 Member

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    I have lately got two 5x7 safelights, one a “Premier”, and the other a “Coastar". They are identical in design and construction but the Coastar is MUCH brighter. The difference is entirely due to the filter, easily proven by switching filters. I have found a way to eliminate the characteristic hot spot, so that both now produce a more uniform glow, and both are an orange hue. However, I am troubled by the difference in intensity and wonder if an intense orange safelight is less safe, so to speak. Being in the early stages of getting darkroom gear together (have not yet taken delivery of an enlarger), I cannot run any tests at this time. Since the instructions that accompany a safelight typically say to keep the light some minimum distance from the enlarger, it would seem that, regardless of hue, too much intensity is a bad thing. How does one test for the safety of a safelight? I would appreciate any thoughts on this issue. Thanks,
    Ted
     
  2. Anon Ymous

    Anon Ymous Member

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    This does the trick for me.

    BTW, you need to test your safelight for any different paper you use.
     
  3. mrmekon

    mrmekon Member

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    I have read that as they get older the filters fade and the safelights get worse. Mine is old and has a crack in it, but still works. The only way to *know* it works is to test it with paper.

    I tested mine by first doing a pre-flash test. Expose paper to white light from the enlarger in 1s increments until you find the first time that makes the paper fade slightly -- do this with NO safelight. Then, preflash another sheet for that same amount of time, then set it maybe 6" from your safelight for significantly longer than you normally would. That depends on your process, I used 5 minutes. Develop that, and see if it's any darker than the one that was pre-flashed and not exposed to the safelight. If they're identical, your safelight is working.

    I know you said you don't have everything together, but this can be done without an enlarger. You do need paper and developer. Pre-flashing evenly without an enlarger will be hard, but I'd try getting two sheets out and flipping on the (dim) room lights for half a second, then process one immediately and expose the second to the safelight before processing.
     
  4. Theo43

    Theo43 Member

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    Thanks guys, I favour an empirical approach, and just needed to get the procedure. Anon, your method is straightforward and looks foolproof; I will go with that.
    Ted
     
  5. fotch

    fotch Member

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    Most safe lights are recommended to be 3 or 4 foot from the paper. I would think any of these safe lights, 5x7, or bigger would fog the paper at 6 inches in seconds.
     
  6. Greg Davis

    Greg Davis Member

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  7. JBoontje

    JBoontje Member

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    I dont have any experience with these safelights as I'm about 2 weeks away from getting my own darkroom started myself, but you could at least change the brightness of the lamp by placing it near a wall. Let the light reflect the wall, this way you will diffuse the light which should make this safelight alot 'safer'.

    I am currently trying to find out whether I should use red or amber safelights, the amber safelight is alot nicer to use (I can see much more) than the red safelight, which seems to be the safest overall. But when I look at the back of my Ilford paper, they recommend amber safelights. Guess I will have to test this myself :/
     
  8. David Brown

    David Brown Subscriber

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  9. Greg Davis

    Greg Davis Member

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    Kodak and Ilford recommend amber with B&W materials because they do not respond much to this color. Red is not as safe unless you are using orthochromatic materials.
     
  10. Anon Ymous

    Anon Ymous Member

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    Amber is closer to green, compared to red. Therefore, red is safer than amber in any case, except of course for panchromatic papers.
     
  11. fschifano

    fschifano Member

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    Red safelights (Kodak 1, 1A, and 2 or equivalents) are most assuredly safe for VC papers. The 1A is the brightest of the bunch and perfectly fine when used at least 4 ft. from the paper. The Kodak 2 filter is very dim and not good for much more than orienting yourself in the darkroom. The Kodak 1 filter is brighter, and can afford some degree of useful visible light, but is still not terribly useful. VC papers are, for all intents and purposes, completely blind to the color of the light emitted by these filters. Red "party bulbs" are not at all safe, and these should be avoided. Amber (Kodak OC or equivalent) safelights are also safe for most VC papers; and as JBoontje pointed out, are easier on the eyes than the red ones. Though I haven't done a side by side test, I'd not be at all surprised if a red safelight provides a higher margin of safety than an amber one. See this document for the spectral output of Kodak's safelight filters. Match the charts up against the spectral sensitivity of the paper you'll be using, and you'll know just how safe your safelight really is.
     
    Last edited by a moderator: Oct 26, 2009