I'm finally getting ready to put the lights into my small darkroom (9' x 7') and would appreciate your input.
I'd planned to used canned lighting: 1 set of 3 for incandescent floods, and another set of 3 for safelights.
Now I'm leaning toward the same plan, but using the spiral fluorescent bulbs instead of incandescent. I imagine the fluorescents would be lousy for color, but for B&W it wouldn't seem to matter too much.
I am not sure with the spiral fluorescents but on the long fluorescents they continue to emit light after being turned off. I would go with incandescents.
Use incandescent. The spiral bulbs I have in the rest of the house emit some UV and do glow for quite some time after being turned off.
Agree with comments above and will add: I used incandescent and put in cans (or high-hats, as they're called some places). In my 7x7 foot space I used 6. It generated a lot of heat and it was quite bright with 60w bulbs. I find that I unscrew the lamps in half of them much of the time.
I wish I had planned a spot for a swinging, articulated drafting lamp. A task light that you can swing about on the enlarging table or on the shelf over the sink would be useful. Since you're in the pre-build stage, I thought it was worth mentioning.
A canned light with a small incandescent bulb a couple of feet over the fixer tray run through a foot switch allows easy, hands-free white light illumination for evaluating a wet print.-I use a 25 watt bulb in a small bullet reflector.
John, Mount Vernon, Virginia USA
I have 3 lighting systems in my DR, all incandescent.
One is bright for general work and uses 8 60W bulbs in overhead fixtures, the second is dim using 2 40 W bulbs for adaptation and work inbetween dark work and the third is 2 15W or 2 7W bulbs in beehive lamps used indirectly for dark work. I use yellow or red safelight for papers, depending on the paper, and I use total darkness for film.
I use the WR13 filter for color printing.
I have flashlights with WR70 filters on them for reading balances and graduate cylinders in the dark. They can be used with directed light for brief moments or can be pointed at my GraLab timer.
At Kodak, we had racks of these flashlights with different filters for different films and papers.
Here is another thought...
Put in three systems:
2) Print evaluation and other special purpose incandescents; and
3) Spiral or other fluorescents for general cleanup etc - uses where you aren't needing to go back and forth between dark and light.
Have the switches for the safelights and incandescents in one location, and the fluorescent switch on another wall.
The fluorescents can be quite bright, without the attendant heat and high energy costs.
Thanks to all - I'm glad I asked!
The advantage of spiral fluorescents is energy savings. The disadvantages are the linger glow problem mentioned by others, and the fact that there is a pronounced warmup characteristic that results in lowered light output for the first minute or so after they are turned on.
In a darkroom, the lights are off most of the time. When you turn do turn on lights, you expect to be able to immediately do whatever you need light to be able to do. Having spiral fluorescents would not be helpful. Yes, you might have to pay a bit more in energy cost for the few minutes that incandescents are on, but because that is likely to be a very small period of time anyway, I think the cost is justifiable in terms of the convenience.
Energy savings is a noble thing to do, but there are times when common sense must prevail. Use incandescents.
Canned lights tend to produce hot pools of light don't they? IMHO thats not very good for safelight conditions. I opted for indirect lighting for my safelight by bouncing it off the white ceiling tiles creating a very even but not overly bright safelight level. This allows seeing down to the floor, under things, etc. that a harsh shadowy light will not allow. I have a direct beehive over the developing tray as well.