Replacing slide projector bulb -- is an LED light an option?

Discussion in 'Film and Processing' started by farkle-mpls, Apr 2, 2016.

  1. I'll stick with SOX in the darkroom, thanks :)
     
  2. - Except those Sodium safelights were designed with industrial-sized darkrooms in mind. They're total overkill in a small domestic darkroom, and might well fog modern super fast multigrade paper.

    Red or amber coloured LEDs are just as monochromatic in their spectrum, and would easily fit in a small 'beehive' or bench-mounted amateur safelight. Warm-white LEDs similarly - but not monochromatic naturally. And there's no starter or hard-to-source ballast to go wrong.
     
  3. LEDs spectral lines are nowhere near as narrow as a low pressure sodium lamp.

    That said, narrow spectral width isn't normally important for safelights.

    It seems that color negative papers, and Panalure, have a narrow low sensitivity region in the yellow,
    which allows for the number 13 safelight. Having used one, safedark would be closer. I once dropped
    some Panalure on the floor, and couldn't see it. They are very dark!

    I believe, though, that there are yellow LEDs that are close to the number 13 safelight, but there might
    be a lot of yellow LEDs that are not so close.

    If you want narrow lines, a semiconductor laser is pretty narrow, though normally multiple modes will
    be active, such that the result isn't all that narrow.
     
  4. Despite the predictions of doom and gloom with using SOX in a small darkroom, I've never had an issue with fogging paper as long as I was halfway reasonable about how I handled it. I'm guessing it would fog if I left a loose sheet out in the open for an hour, but I'm typically 5 minutes or less from out of the box to the time I'm in the developer, and using the "penny test" I only start to see the faintest traces of fogging after about 30 minutes.

    I like the fact that my darkroom is bright enough that I can read things like the filter chart taped to the head of my Focomat without straining.
     
  5. I have three safelights with 0C filters, installed by the previous owner.

    It would be four, but I put a 13 filter in one of them.

    That is plenty bright, but one LPS lamp might be nice, too.
     

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