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  1. #21
    pcyco's Avatar
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    hallo

    jerevam: i never thought about this. im a redlightarea-worker

    i tried it because a friend of mine got a strip of red lights, which he used as darkroomlight.
    it was bright as hell. you were unable to see anything of the negativeprojection on the paper.
    these times we were looking which led these were etc. but there were noch chance to find it out.
    so i tried the philips bulb.

    maybe you can talk to the guy in the shop to test serveral lamps. and give the rest back. and when they all work its brighter

    and lets know us which works well -> when you are testing.

    thomas

    ps.: maybe sometimes we think a little bit to much about everything before we do it.
    lets try it!!! and see whats happen. last days i made a papernegative with my plotter on transparent drawingpaper at my work.
    a strange look. athers will never try this because of this and that and they will never explore new ways. it will be much more important to write down and comment what happens and tell it to the others so they can do it also.
    --------------------------------------------------
    vfdkv (259)

  2. #22
    Jerevan's Avatar
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    Pcyco,

    I looked around at the Philips site and think I maybe found the light you are using. I'll have to go to the shop and see if I can order one to test it out.

    And yes, you are right - the only way to find out is to try. As a famous writer once wrote: "Try again. Fail again. Fail better."
    “Do your work, then step back. The only path to serenity.” - Lao Tzu

  3. #23
    pcyco's Avatar
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    hallo

    "Try again. Fail again. Fail better." great

    will you try the green one too???

    let me know when it works!!

    --

    thomas
    --------------------------------------------------
    vfdkv (259)

  4. #24

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    Green will not work! check out the wavelength.

    Red or amber will be fine.

  5. #25
    Jerevan's Avatar
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    Yes, I will check back as soon as I get down to it.

    As you say, Irvine, the green will not work - it was too late at night when I wrote that, that's my feeble excuse.
    “Do your work, then step back. The only path to serenity.” - Lao Tzu

  6. #26
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    It's not just about wavelength, an LED with a "safe" wavelength range (e.g. a red LED) can and will fog paper if there is enough intensity. I've attached the SED of a flashlight that I measured (that I use- carefully - in the darkroom), output is zero shorter than about 575nm but it will definitely fog MGIV RC paper if you hold it close for a few seconds.
    The answer is always to test, there are detailed but easy to perform methods described on Kodak's site
    Attached Thumbnails Attached Thumbnails red LED flashlight SED.jpg  

  7. #27

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    Quote Originally Posted by thisismyname09 View Post
    ......... LEDs will only give off a certain frequency of light, nothing more.............
    Unfortunately this is not generally the case. I am using my mark 3 LED safelight after the first two (one amber, one orange-red) were found to fog VC papers (Agfa and Ilford). My current one has extreme red LEDs and is very safe even at a high intensity.

    Try this (thanks to Paul Butzi for the idea):

    Look at the light of the LED reflected from the base of a CD at the angle that gives the "rainbow" effect. You will probably be surprised to see quite a range of colours from red through orange, yellow, green and even aqua. I think it's hard to judge the amount of each colour, though.

    The spectrum graphs supplied by LED manufacturers shows the spread measured in arithmetic units, not the familiar logarithmic units used by photographers, so the spread is worse than it seems from a quick glance of the graph.

    If someone finds an orange LED with very little spread please tell us all!

  8. #28
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    Quote Originally Posted by Mainecoonmaniac
    Quote Originally Posted by michaelbsc View Post
    I don\'t have a bright darkroom. I use a few small 5x7 housings that I\'ve collected cheap over the years to illuminate specific work areas and let the rest of the room be dark if the white lights are off.



    Searching the floor is a little hard if I drop something, since there\'s little illumination outside the spots. But I never worry about fogging anything.
    The Thomas Duplex safelight was a salvaged from my work place. It was 10 years ago when the university started closing darkrooms at reasearch labs. I also got an Arkay tumbling print washer too.
    The safelight is good.

    YMMV, but I think that print washer is an instrument of the devil.
    Michael Batchelor
    Industrial Informatics, Inc.
    www.industrialinformatics.com

    The camera catches light. The photographer catches life.

  9. #29
    pcyco's Avatar
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    hallo

    yesterday i tested the led again.
    distance to the paper aout 30 cm.

    12 minutes -> absolute nothing. white, white white.
    --
    thomas
    --------------------------------------------------
    vfdkv (259)

  10. #30
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    I passed by the local store (local to my lab, anyway) the other day and asked them to get some of the red LED bulbs so I can try. Will report back when I get my hands on them.
    “Do your work, then step back. The only path to serenity.” - Lao Tzu

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