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Thread: Red compact fluorescent bulb as a red safelight.

  1. #1

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    Red compact fluorescent bulb as a red safelight.

    Went to process some orthchromatic film and my little round red "safelight" bulb wouldn't light up so I replaced it with a red compact fluorescent bulb and proceeded to process the film. As I was tray processing the film, I could see that it was fogged. Retrieved the little incandescent bulb from the trash and tried it again and it worked, evidently it had become loose in the socket. Anyone else have a similar experience with red compact fluorescent bulbs?

  2. #2

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    Re: Red compact fluorescent bulb as a red safelight.

    no. No cfl's in my house. I've been using the same $4 red safelight bulb from freestyle for the last 10+ yrs.

  3. #3
    A.K.A Lucky Bloke ;-)
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    Re: Red compact fluorescent bulb as a red safelight.

    Quote Originally Posted by Greg View Post
    Went to process some orthchromatic film and my little round red "safelight" bulb wouldn't light up so I replaced it with a red compact fluorescent bulb and proceeded to process the film. As I was tray processing the film, I could see that it was fogged. Retrieved the little incandescent bulb from the trash and tried it again and it worked, evidently it had become loose in the socket. Anyone else have a similar experience with red compact fluorescent bulbs?
    Allow me to suggest looking for a pure red led lamp dimmable. Still, you should use it with the dimmer as low as possible. The auction site, home depot or even walmart should have it in stock.

  4. #4
    Resident Heretic Bruce Watson's Avatar
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    Re: Red compact fluorescent bulb as a red safelight.

    Quote Originally Posted by Greg View Post
    Anyone else have a similar experience with red compact fluorescent bulbs?
    It's a fluorescent. It uses mercury as a conductor, yes? And energized mercury gives off a spectrum that's largely a big green spike. That's why they use mercury BTW; it's not an artifact, it's efficiency (lumens/watt). Unless they fully filter the green out (which would make the light from the bulb very dim, which in this case may not be a bad thing), you probably gave your film a big dose of green light. Fog city.

    I personally just love it when physics jumps up and bites me on the rump like that. :-(

    Bruce Watson

  5. #5
    jp's Avatar
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    Re: Red compact fluorescent bulb as a red safelight.

    The CFL bulb has glowing phosphors that put out all sorts of colors (including big spikes from the light that activates the phosphors). The red is just a filter that reduces but does not eliminate the other colors.

    A red incandescent puts out warmer colors so there is less variety of colors and no color spikes to filter.

    I use red LEDs. They are oldschool (cheap) LEDs that work without phosphors and their spike is their monochromatic red color. Plenty has been written on here what to get and how to test them.

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