Divided Pyrocat: Marks on negs from the inside ridges of 8x10 BTZS tubes?

[mikew]

I swear that the pyrocat gods hate me...

So I've been playing around with manipulating CI using divided pyrocat processed in 8x10 BTZS tubes (my negs are a zone VII exposure of an evenly illuminated surface within 1/5 stop). But as the CI increases I'm noticing that the ridges inside the tubes are leaving impressions of some kind - maybe stain? The process that I'm currently using is:

- FP4, Pyrocat-P, 75F, Part A 1:6 w/ a few drops of working photoflo solution, Part B 1:6
- 5min presoak @ 75F
- Agitate Part A by shaking tube for first 30sec then spin (on counter or in bath - I've done both because I find that the tubes don't spin well in a bath - at all - and that my results are uneven)
- 15 sec drain
- Agitate Part B by shaking tube for first 1min then spin as above
- stop or water stop
- rapid fix out of tube 5min

I've read about every post on these boards, and others, regarding uneven development and different agitation cycles and methods but I haven't come across anything that addresses this issue.

I'd love to hear people's thoughts.

Thanks everyone,

Mikew

[Kent Berquist]

I've encountered the same problem with the BTZS tubes and Pyrocat. I now do semistand development with JOBO tanks (the ones without the without ridges) and never have this problem.

[mikew]

Thanks for that Kent. Which Jobo tank do you use?

[Kent Berquist]

A 1530 stacked upon a 1520...holds one 8x10 sheet. My impression was that the ribs on the 8x10 BTZS tubes allowed enough developer to get underneath the film to cause differential staining of the non-emulsion side of the film which may not be apparent to the naked eye but results in streaks on the final print, especially Pt/Pd prints. Note that the 4x5 BTZS tubes have no ribs and I have never had a problem with Pyrocat HD with them.

[mikew]

A 1530 stacked upon a 1520...holds one 8x10 sheet. My impression was that the ribs on the 8x10 BTZS tubes allowed enough developer to get underneath the film to cause differential staining of the non-emulsion side of the film which may not be apparent to the naked eye but results in streaks on the final print, especially Pt/Pd prints. Note that the 4x5 BTZS tubes have no ribs and I have never had a problem with Pyrocat HD with them.

That's around what I was thinking too. I messaged Sandy and he confirmed that surfaces with ridges would cause marking. Thanks for the response Kent.

[Jim Noel]

The best solution and the one least likely to cause problems is to learn to develop negatives in a tray. No tube, or hanger has ever equaled the consistency and lack of equipment induced problems as a flat bottomed tray and ample chemistry.

[mikew]

Jim - I think that the solution is relative. When I was using Rodinal, HC-110, D-76 and Xtol I did all my processing in trays and had no issues with unevenness. Those techniques, however, haven't worked with the Pyrocat formulas (which is why I've been experimenting with tubes). But that statement needs to be qualified. I'm basing my success on being able to develop a negative exposed to a surface of even luminance - within 1/5 stop - to +/- log .03. I am able to get even development with different developing techniques, I just haven't been able to produce consistent results when processing a neg with large areas of even tonality using methods designed to enhance adjacency/compensating effects like minimal agitation or divided development. I hear what you're saying though. It's always best to simplify what you're doing to minimize the number of variables that you're dealing with. Thanks.

[Brian Ellis]

Are these ridges something new? I had some 10-15 year old 8x10 BTZS tubes and I don't remember any ridges.

I never liked standing in the dark for 10-15 minutes jiggling trays of liquid and inhaling chemical fumes so I stopped using trays for 8x10 as soon as I acquired the BTZS tubes. Of course I wouldn't like ridges that create marks on a negative either. Fortunately my 8x10 tubes either didn't have ridges or if they did they didn't leave marks on the negatives using D76.

[mikew]

Are these ridges something new? I had some 10-15 year old 8x10 BTZS tubes and I don't remember any ridges.

I never liked standing in the dark for 10-15 minutes jiggling trays of liquid and inhaling chemical fumes so I stopped using trays for 8x10 as soon as I acquired the BTZS tubes. Of course I wouldn't like ridges that create marks on a negative either. Fortunately my 8x10 tubes either didn't have ridges or if they did they didn't leave marks on the negatives using D76.

I'm not too sure how new the 8x10 BTZS ridges are but they're entirely different than the 4x5 tubes which are just flat tubes. I suspect that only a pyro-type developer would produce the kind of marking that I've experienced because the ridges - which I assume are intended to facilitate wetting of the back of the film - are actually causing uneven staining on the back of the film. But I've only noticed this when using divided pyrocat. I don't recall seeing it when using the BTZS tubes regularly.