Problems with semi-stand agitation and pyrocat

[pwitkop]

I've recently been shooting more roll film, and have been using pyrocat with intermitant agitation (10 inversions every minute), butwas experimenting today with semi-stand aggitation. The test roll I tried yesterday looks pretty good, maybe a little flat, but pretty good for a gues at the time, with one exception, I'm getting underdeveloped (almost undeveloped) patches near one side of the roll. I'm not sure if it's the top or the bottom, I didn't notice them until they were hanging, so I could tell which way the film was in the tank, but the problem only occurs on one side. I had an empty reel on the top, and the one with film on the bottom. Agitation was continuous for the first 60 seconds, and 10 inversions every 3'rd minute. I was using a jobo 1500 series tank (the one that takes two 120 sized rells, don't recall the number), with jobo plastic reels. I wonder if the reels had anything to do with it, as they don't leave a lot of room between the film, but I've never had any problems with them in the processor, or with my ussual inversion routine. I ussually use stainless reels when hand processing (the jobo tank is ussually only used on the processor), but both my SS reels managed to grow legs the last time I used them in the lab at school :-/ I've attached a scan of the negs below, as I'm sure it's a better explanation than I can describe. Any ideas on just what's going wrong, or how to avoid this are greatly appreciated.

Peter

 

[glbeas]

Looks like airbells to me. You might try slamming the tank on the table a time or two after you get the developer in.

 

[pwitkop]

I didn't really think of air bells since it was pretty consistant on all frames, but that would make sense if there were air bubbles around the top edge of the reel. I'll have to try again with stainless reels (I'm thinking they might be less prone to hold air bubbles?), and giving the tank a good rap after each agitation.

Peter

 

[mark]

The only time had trouble with air bubbles was in a SS tank with SS reels. No matter what I develope in or what reels, I give it a whack after the agitation. It can't hurt.

 

[sanking]

I didn't really think of air bells since it was pretty consistant on all frames, but that would make sense if there were air bubbles around the top edge of the reel. I'll have to try again with stainless reels (I'm thinking they might be less prone to hold air bubbles?), and giving the tank a good rap after each agitation.

Peter

Did you presoak the film? A five minute presoak is generally recommended with minimal and semi-stand agitation.



Sandy King

 

[pwitkop]

I did do about a 6 or 7 min. pre-soak, with agitation most of the time, except when I was tempering the water for the developer, mixing, etc. I do tap the tank after agitation, but in this case I was processing at home where I process on my bed (don't like using the chemistry in the kitchen, and there are 3 of us in the apt., so I can't monopolise the bathroom) with a painters tarp over the bed (since I don't like my sheets smelling like chemistry, even if most of my cloths do), so I was just taping the tank with my knuckles, which might not be as effective as taping it vertically against a hard surface.

Peter

 

[mark]

A large book (mine was a survey of english lit book) works great for on the bed processing when you need to whack the container. I used to process this way too.