What is causing black granular spots on my negs?greenspun.com : LUSENET : B&W Photo - Printing & Finishing : One Thread
I have been experiencing a problem in black & white developing with a liquid mix D-76 used in a 1:1 ratio. Sometimes it is with the first use of a fresh mix, other times it occurs when I reuse the solution a second time. My negs have small black blotches randomly spotted over the film. Is this an agitation problem? Should I filter the stock solution or what?
-- Wayne Little (firstname.lastname@example.org), March 26, 2002
Are the blotches in the emulsion or a foreign substance sticking to the film? Either way, try mixing the D-76 with distilled water. I wouldn't filter the D-76 unless something's floating in it after the powder is all dissolved. And if something is floating in it, check your water supply. I've had tiny spots form on film during development. These printed as black spots. I decided they were caused by the fact that the D-76 stock solution was made by dissolving the powder in water from the hot tap, which apparently produces some gas bubbles for a time. I now dissolve the D-76 in 110-degree water made by taking water from the cold tap and heating it on the stove. Also, the 1:1 dilution is usually used once and discarded, although reuse shouldn't cause black blotches.
-- Keith Nichols (email@example.com), March 26, 2002.
Try presoaking your film for 1-2 minutes before processing. It sounds to me like these spots are occurring during the time it takes you to fill your tank before you begin agitation. Droplets of developer may be at work on your film for several seconds before you completely fill your tank. Presoaking will lessen this problem. You could also fill the tank first, then put the film in (in the dark, of course).
-- Ted Kaufman (firstname.lastname@example.org), March 27, 2002.