I'm frustrated. I've been plagued recently by several annoying problems in my black and white film developing. You can see some recent posts -- a stain here, a mark there. Usually they're not egregious, but they tell me something's wrong. One exception is the presence of what are clearly air bells along the top edge of a roll of 120 (Acros 100) which was the top roll in a Paterson 3 tank (see image). I use 1200ml of solution in this tank which leaves a good half inch above the top reel. So I don't think "use more solution" is the remedy. I always knock the tank a few times after agitating.
I have changed some things in my process lately, though not all at once. I'm using Perceptol less and HC-110 more; recently I settled on dilution E. I upgraded to a larger Paterson tank (two rolls of 120 instead of one). I also began using inversion as my initial agitation to correct another problem which may or may not have been agitation related (previous I was doing stick rotation).
I don't want to change every variable at once to try to correct my problems. Nor do I want to make and process a bunch of test rolls before processing "critical film" (though I will if I have to). The way I see it, I could try one of three things:
1. Switch back to rotation/stick agitation. 1200ml makes the tank quite full. It calls for 1000ml, but that leaves the top reel partially exposed. I know with inverting, it takes time for the solution to run through the funnel, thus the top edge of the top roll is exposed to air the most time. But air bells are a "tank at rest" problem, I think, so I don't know if this makes sense.
2. Prewet the film. I've heard this solves a lot of uneven development problems for a lot of people, but have read a lot of things against it too. I prewet for C-41 always, but hardly ever for black and white. (And ironically [or not] I don't have these problems with my color negative processing.)
3. Use a less active HC-110 dilution -- like dilution H.
I've been doing black and white film for about five years -- which hardly makes me a pro, but I've not had these types of problems before. Or maybe I just haven't looked hard enough. Anyway, I'm curious to hear your thoughts. Thanks.
I have changed some things in my process lately, though not all at once. I'm using Perceptol less and HC-110 more; recently I settled on dilution E. I upgraded to a larger Paterson tank (two rolls of 120 instead of one). I also began using inversion as my initial agitation to correct another problem which may or may not have been agitation related (previous I was doing stick rotation).
I don't want to change every variable at once to try to correct my problems. Nor do I want to make and process a bunch of test rolls before processing "critical film" (though I will if I have to). The way I see it, I could try one of three things:
1. Switch back to rotation/stick agitation. 1200ml makes the tank quite full. It calls for 1000ml, but that leaves the top reel partially exposed. I know with inverting, it takes time for the solution to run through the funnel, thus the top edge of the top roll is exposed to air the most time. But air bells are a "tank at rest" problem, I think, so I don't know if this makes sense.
2. Prewet the film. I've heard this solves a lot of uneven development problems for a lot of people, but have read a lot of things against it too. I prewet for C-41 always, but hardly ever for black and white. (And ironically [or not] I don't have these problems with my color negative processing.)
3. Use a less active HC-110 dilution -- like dilution H.
I've been doing black and white film for about five years -- which hardly makes me a pro, but I've not had these types of problems before. Or maybe I just haven't looked hard enough. Anyway, I'm curious to hear your thoughts. Thanks.
) equipment.