In the basement workshop where I set up my darkroom is a recessed light fixture in the ceiling. With a 50 watt light bulb and two layers of red gel. (Rosco #R-27.)
From the center of the room, it is a good six feet away from my work areas where I open my sensitized goods. My safelight tests show that most paper can be in the open for 15 to 20 minutes or more before any noticeable fogging begins to occur.
Actually, I'd have to disagree with the idea that it must be dark red and it must be 4 feet away. I have insanely bright red and yellow LED bulbs (OptiLED) and they both seem to be safe for all papers. I bought both colors since I thought papers like Slavich would need it. I routinely use them both for lith printing (development up to 10 minutes) without fogging. LEDs are nice because they act over a very narrow wavelength band.
I really don't think that was particularly big disaster you describe. Now when you fog an entire box of paper for the second or third time......let's just say that I've invested in multiple paper safes!
I'm not saying that safelights HAVE TO BE red. I'm just saying that this particular shade of red works pretty well for my application.
(Which is developing regular black and white papers and similar.)
Rosco #R-27 theatrical gel blocks almost everything with a wavelength smaller than 580 nm. and transmission doesn't hit 10% until you get to 620 nm. R-27 transmits only about 4% of the total light. The specs say the stuff knocks off 4.7 stops.
One sheet ought to do it but two sheets sandwiched under frosted glass gives pretty good safelight protection.
I like the idea of the LED lamps. Their bandwidth is so narrow that they are virtually monochromatic like a sodium vapor lamp. The next time I am in the market for safelights I'll definitely be looking into LEDs.
(BTW: Do sodium vapor safelights give anybody else a headache after you've been working in them for a while?)
I use 1A (light red) safelights in 5x7 fixtures with 25watt bulbs pointed at the ceiling. They are more than 5 feet from the work area but provide enough light to read by. No fog at all with my tests up to 20 minutes with most VC papers.
A disaster was when I worked in a xray lab. I left the film safe open when I opened the door. Hundreds of sheets of different sizes ruined.:( Didn't get fired though :laugh:
I used red film foil that is used for theathre lamps (in front). I guess it was about 620nm. That means that light lower than that will not pass the red filter and kill your print. paper is only visible to about 560 so if you use a filter above that it will be fine.
I made a wooden box with a 7watt lamp that produces 20 watt. It has a long life and about no heat. I tested it with one sheet of foil distance 1 meter. And guess, the paper was still fogged (i take 10 minutes as a test time because when lithing this is the time needed). When I used 3 layers of foil, it was fine for 10 minutes.
Seems like one layer of foil still has some holes in them which spread the normal light.http://www.adox.de/ADOX_Papiere/Vari...s/page16_4.jpg
Last evening I made some print using the new bulb (7w) for the safelight. No fog at all, everything went fine. Anyway, I didn't mean to say that wasting one piece of paper is a disaster, the disaster was the fact that the electricity in all the room went off, and we had to mess up with the wiring, I really feared that the accident had made the enlarger stop working...
There is a saying that "It always looks the darkest before a storm". Actually, it always looks the darkest when the safelight fails.
Originally Posted by Monito
Glad to hear all is back in order, now let's see that serene print you were working on
That one is still wet, but this is taken in the same place.
Originally Posted by zsas