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  1. #11
    Ken Nadvornick's Avatar
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    I have been using the red version of these standard base S-11 Festival LEDs with spectacular success. Pre-fogged testing with Ilford MGIV, both FB and RC, shows no safelight-induced fogging out to at least 60 minutes.

    The only caveat is that none of the LEDs I tried emitted absolutely pure light. In addition to the main peak centering on the design wavelength (635nm in this case), the S-11s were also generating small blue and green spikes. I could see these clearly by simply observing the light reflected in a standard CD disc. These spikes did add to the paper fog levels after a few minutes exposure.

    I solved the problem by enclosing the bulbs under a single layer of Rubylith. This acted as a poor man's low-pass filter, effectively blocking the higher frequency spikes while passing almost all of the lower frequency red light.

    The blue and green disappeared from the CD, and the safe exposure times for the papers jumped to the 60+ minute mark. (I stopped the test at that point, so I don't know how much further it might have been able to go.)

    I eventually hacked up a DIY bank of six of these bulbs to create a relatively bright working environment.

    Ken
    Last edited by Ken Nadvornick; 01-04-2011 at 04:23 PM. Click to view previous post history. Reason: Corrected the wavelength value...
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  2. #12
    Kevin Kehler's Avatar
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    Quote Originally Posted by MattKing View Post
    These work well as safelights in standard fixtures, using Ilford MGIV-RC, Kodak Polycontrast RC and, IIRC, Oriental RC:

    http://www.dealextreme.com/details.dx/sku.5136

    They are bright and operate without much heat. They are also very inexpensive and are shipped quickly. My only problem is that they don't pack them all that well.
    I actually just ordered 4 of these last week (they are not here yet); have you used them with FB paper (you only list some RC papers). I would assume they would be safe (and I plan on testing them) but am looking forward to being able to see a little better in the dark.
    Once a photographer is convinced that the camera can lie and that, strictly speaking, the vast majority of photographs are "camera lies," inasmuch as they tell only part of a story or tell it in a distorted form, half the battle is won. Once he has conceded that photography is not a "naturalistic" medium of rendition and that striving for "naturalism" in a photograph is futile, he can turn his attention to using a camera to make more effective pictures.

    Andreas Feininger

  3. #13
    MattKing's Avatar
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    Quote Originally Posted by Kevin Kehler View Post
    I actually just ordered 4 of these last week (they are not here yet); have you used them with FB paper (you only list some RC papers). I would assume they would be safe (and I plan on testing them) but am looking forward to being able to see a little better in the dark.
    Kevin:

    I use RC almost exclusively, so no tests with FB I'm afraid. FWIW, my MGIV RC tests include the regular, warm tone and cool tone versions.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  4. #14
    Steve Smith's Avatar
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    Quote Originally Posted by MattKing View Post
    I use RC almost exclusively, so no tests with FB I'm afraid.
    If it works with RC it should be the same with fibre. It's the same emulsion on the surface.


    Steve.
    "People who say things won't work are a dime a dozen. People who figure out how to make things work are worth a fortune" - Dave Rat.

  5. #15
    23mjm's Avatar
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    These LED bulb looks promising to me both in Red and Amber. Might have to give them a try they are cheap enough and the give spectral graphs of the colors.

    http://www.superbrightleds.com/cgi-b...%2FE27-W24.htm

  6. #16
    Ken Nadvornick's Avatar
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    Quote Originally Posted by 23mjm View Post
    These LED bulb looks promising to me both in Red and Amber. Might have to give them a try they are cheap enough and the give spectral graphs of the colors.
    As mentioned above, beware of the minor secondary and tertiary emission peaks in other non-red parts of the spectrum.

    When other threads have mentioned unexpected fogging from what they assumed from the manufacturer's spectral graphs to be pure LED colors, this was likely the culprit.

    Without the Rubylith addition to my red LEDs my papers were demonstrating noticeable additional fog in as little as 10 minutes or less.

    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  7. #17
    Kevin Kehler's Avatar
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    Quote Originally Posted by Ken Nadvornick View Post

    Without the Rubylith addition to my red LEDs my papers were demonstrating noticeable additional fog in as little as 10 minutes or less.
    I am going to get a little off topic but is it normal for people to leave paper out for that long? I always was told to the last thing you do is take paper out, expose as soon as possible (everything should be ready to expose prior to removing paper from package) and develop immediately. Given my constant walking in and out of the darkroom for fresh air and to wash (bathroom is down the hall), I guess that length of time has never been an issue for me as all of my paper stays in its' package unless being used immediately.
    Once a photographer is convinced that the camera can lie and that, strictly speaking, the vast majority of photographs are "camera lies," inasmuch as they tell only part of a story or tell it in a distorted form, half the battle is won. Once he has conceded that photography is not a "naturalistic" medium of rendition and that striving for "naturalism" in a photograph is futile, he can turn his attention to using a camera to make more effective pictures.

    Andreas Feininger

  8. #18

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    Okay, I have a few standard (read old) 5x7 inch safelights, with the 1A red filters. Since normal replacement lightbulbs are hard to find (15watt), could I use one of the LED bulbs mentioned here? The filter should be about the same as rubylith.

  9. #19
    23mjm's Avatar
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    The extraneous light emissions can be said of all safety lights. As with anything a little testing can go a long way. My little 5X7 light uses a 15 watt bulb, when it goes I will get a red and amber LED light and stick in the housing without the filter and see how it works.

    Quote Originally Posted by Ken Nadvornick View Post
    As mentioned above, beware of the minor secondary and tertiary emission peaks in other non-red parts of the spectrum.

    When other threads have mentioned unexpected fogging from what they assumed from the manufacturer's spectral graphs to be pure LED colors, this was likely the culprit.

    Without the Rubylith addition to my red LEDs my papers were demonstrating noticeable additional fog in as little as 10 minutes or less.

    Ken

  10. #20
    Ken Nadvornick's Avatar
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    Quote Originally Posted by Kevin Kehler View Post
    ...but is it normal for people to leave paper out for that long?
    It depends on the workflow.

    I use that Aristo VCL4500 variable contrast light source. Even with brand new tubes it was never designed to be high-intensity. Base exposure times of a couple minutes are not uncommon, especially for larger prints.

    I also use a standard development time of 4-minutes in home-brewed Ansco 130 for my fiber-based paper. This can occassionally expand to 6-minutes, if the desired effect calls for it.

    Add to the above the occassional complex dodging and burning sequences - sometimes using multiple contrast grades - which I design for repeatability around multiple 3-second omissions and bursts, and the time can add up.

    Between exposing activities I do have a large black sheet of construction paper that I lay over the easel to keep safelight exposure to a minimum. But creating and developing a complex final print can sometimes take over 5-minutes to complete.

    When I tested for safelight fog I did so in 5-minute increments. Without the extra filtration I noticed additional fogging somewhere between the 5- and 10-minute steps. This was too close for comfort to my worst-case printing scenarios.

    I realize that a lot of workers prefer quick, single exposures of 10-seconds or less, followed by immediate RC development times of perhaps only 90-seconds, and not much in the way of dodging or burning. For this workflow 5-10 minutes open time is more than sufficient, if not overkill.

    I just want to make the point for those who might read this thread later that if their open times run longer like mine sometimes do, one source of unexpected fogging (highlight degradation) could be the light from those LEDs that they might have been led to believe was pure.

    It's worth noting that I was not originally looking for 60+ minutes. That is overkill in the other direction. It just turned out that a single layer of Rubylith over a 635nm LED produced an extraordinarily pure red light, and was a perfect match for the two Ilford papers. And I thought that discovery was worth mentioning.

    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

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