Post flashing

[Bill Burk]

Reciprocity law failure would be significant and easily studied, depends if the flashing light source is dim for long time (unsafe safelight) or bright for a short time (electronic flash tube). Intermittency if a pulsed-xenon flashing light source is used. Latent image keeping issues if you decide to preflash a whole box of paper and then store it for a month before using. All these things can be figured out separately.

 

[NedL]

Ha! Maybe nobody intentionally uses an unsafe safelight or pulsed xenon to flash, but I've got a big envelope of paper that I flashed in June 2012 and am still using occasionally. I wonder how long it will be before latent image keeping will come into play. I'd think it might be noticeable, because the speed difference from flashing for paper negatives is fairly dramatic and the exposure is fairly critical. Even though I have no densiometer or other objective measure, it would have to be a relatively small effect or I'd notice problems.

I've also kept paper negatives for several months before developing with no obvious visible problems.

But we are talking about different things. I'm guessing your tests could easily reveal differences that might not be noticeable to my eye in a paper negative. Differences that could matter if you were making a highly controlled fine print. I'm not suggesting people keep batches of pre-flashed paper for printing either.