I am building a darkroom in my basement, and I came upon this question: When I bought by 10x12 OC safelight filter, the guy at the store said to only put in a 30 watt bulb or lower, otherwise the plastic filter would melt. After putting in a 20 watt, which was all I had on hand, and recieving poor results, I put in a flourescent 90 watt equivalency bulb. While the actual wattage of the flourescent bulb is only about 23 watts, the light output is much higher, it will probably not melt my filter, but will that much light damage prints I make?
As I recall, florescent(sp?) lights give off UV rays, which can fog paper.
REGARDLESS of what TYPE of safelight you use, OR wattage, you SHOULD perform a fog-test before doing prints.
To do this, mount any (at least semi-good) negative in the enlarger. Do a test strip and develop using your usual procedure.
Then, place a piece of paper (or another test strip) under the enlarger. Half expose the paper. (ie: if proper exposure was 8sec, expose for 4sec)
Take the paper out and place it on your work table. Place a number of coins on the paper, and leave it for twice as long as you would ever leave paper before the developer.
For instance, I always go straight from the enlarger to the developer...but occasionally the phone might ring, and paper might sit for 2 minutes before I get to the developer. Thus, I leave the paper/coins out for 5min on the work table.
Develop the paper as normal. If you can see the outline of the coins, however faintly, the safelight is NOT safe...if you can't see the coins, you're safe.