More time or more watts?
I'm new to wet printing, so this may be a completely dumb question.
I've got some negatives that are quite heavily fogged, either due to process experiments that didn't work quite as hoped or to being shot on really old film (some of them are on glass plates that were ~65 years old when I exposed them). I can print through the fog one of two ways: wait a really long time, or use a brighter bulb (or move the existing one closer). Does it matter which I do? Is there any significant way in which paper reacts differently to length vs. intensity of exposure, or is it all the same as long as the right number of photons arrive?
(I'm printing mostly on Fomalux 312, which is contact speed, and a little bit on Ilford MGIV in an effort to reduce the exposure times for some of the more bulletproof negatives.)
This would mostly depend on the times you need. However, I would tend to use brighter lights rather than longer times. The reasoning is, longer times make fogging the print more likely.
If you use reeeeeallllly long times, turn off your safelight so you don't get safelight fogging.
Stronger light to get shorter times is way more convenient, and you'll be more willing to do an extra test print etc. when the exposure time doesn't seem so long. Even thought there is no theoretic reason long exposures would produce any lower print quality, in practice, you will often get better results.