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03/15/2009 10:49:03 PM · #1 |
A little bit off topic, but I know some (many?) of you know a thing or two about the darkroom.
I need a quick and dirty safelight -- something cheap that I can build from materials around the house. Any ideas? Can I throw some red cellophane around a small flashlight or bury the flashlight in a plastic red cup? What about an LED display clock radio? A small red Christmas lightbulb in a night light?
This is just an experiment for me right now, and I don't want to invest too much in it up front. I'm developing black and white paper.
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03/15/2009 10:50:38 PM · #2 |
Safelights are traditionally 5w or less and buried behind a rather thick red cover. You will need something that is so dim that it actually takes your eyes a couple minutes to adjust to the fact that it's on in order to not create safelight fog on your film before it's processed.
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03/15/2009 11:19:00 PM · #3 |
| From what I understand, it has less to do with wattage and more to do with wavelength. Red light bulbs should work fine and some yellow (amber) ones will also do the job but you just have to keep track of how long the paper is exposed to it. What I would recommend is testing the light by placing a coin or something on a piece of photo paper then develop it to see if it shows up. It is also my understanding that cheap red LEDs will do the job. |
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03/15/2009 11:36:50 PM · #4 |
| if you buy a red lightbulb or leds make sure the entire bulb is covered with the red, sometimes they arnt around the base |
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03/15/2009 11:43:54 PM · #5 |
The wavelength is not a real issue since all visible light is relatively close in wavelength. Its the intensity that is key, and red is choice because of most film's lack of sensitivity to red light. The key is as dim as possible and as far away from the film/paper as possible.
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03/15/2009 11:52:10 PM · #6 |
Originally posted by jmsetzler:
The wavelength is not a real issue since all visible light is relatively close in wavelength. Its the intensity that is key, and red is choice because of most film's lack of sensitivity to red light. The key is as dim as possible and as far away from the film/paper as possible. |
Umm, the color of light is determined by its wavelength.
For B&W paper, there are narrow band safelights that are similar in color to sodium vapor streetlights. They are much brighter than the amber filters that are placed over ordinary incandescent bulbs. They're expensive, so probably not what teh OP is interested in |
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03/16/2009 12:16:27 AM · #7 |
The type paper that you are using will determine the safe light that you will need. Lithographic paper usually is not sensitive to red light, while orthographic paper is sensitive to the greens and blues, and needs a yellow safe light. Panchromatic paper is sensitive to all wavelengths, so should be processed without a safe light, until the paper is placed into the fix bath. The data sheet for the paper that you are using should list the recommended safe light filter. B&H has an OC filter, suitable for orthographic paper for $9.50 that can be taped over any low wattage lamp.
//www.bhphotovideo.com/c/shop/535/Safelights_Accessories_Safelight_Filters.html
Message edited by author 2009-03-16 00:19:02. |
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