Well, I'm no where near as experienced as other shooters but I'll stake a claim and that's my theory for now ... There is something causing the ridge steaks at least with some pyro developer mixes and some tanks/agitation schemes/processes maybe we could throw in film size and type also (?) but weather or not they are noticed is dependent on the subject and associated UV printing of the neg ...
Originally Posted by photomc
A lot of variables !
Its a hard nut to crack huh - any physical solution I come up with in terms of another way to hold the negs in the tube I get the feeling I'm just going to introduce another issue ...
Anyway to 'float' a neg on a solution of bleach that would clear the base side of stain but via surface tension at the edges keep the emulsion dry ? :rolleyes:
PMK has a hard time in roller processing because it is a fast oxidizer. I use B&S rollo pyro, which behaves much as pmk but it has an inhibitor tht slows down the oxidation. Nice stain, no streaks. Hutchings new Max Pyro is said to be good for jobo etc as well.
Question is, is the faster oxidation the cause of the base side ridge concentrations ?
Originally Posted by JBrunner
I'm going to do a B&S order in the next few months - maybe I'll get both Pyrocat-Hd and the Max ...
Oxidation. The only two techniques I've had success with are as follows...
1. Fill tank with two litres of solution (in my case a 3006 Jobo drum) and use a rubber plug to plug off opening and then hand rolled in the trough of my cpp.
2. Nitrogen gas fed in through the "nostrils" of the lift at a rate of 1000 ml/minute during development.
The rib markings are weird as they're not on the emulsion side of the neg. right? How you pre-wash seems to have an effect. I found that, for the pre-wash, filling up drum to the lip with distilled water and then inserting sheet film in slots was the only solution to this problem.
Ok - whew, depending on the drum that's a lot of distilled water :o - the room I load film in isn't of the wet variety unfortunately ...
Originally Posted by frotog
Reverse engineering your solution doesn't give me any clues as to the action of the issue itself though - ok, so now the film is wet, but how much or less 'wet' than an initial pre-wet via the usual method of less un-distilled water and a bit of agitation ... (?)
Perhaps a bit off topic but I did some 4x5 E6 yesterday in two identical model drums - the little 2000 series ones that can do 2x 4x5" - 2 frames from one of the drums came out with sort of 'gummy' strips where the rib sat on the base, one frame it cleaned off fine, the other left strips of abrasion, perhaps from a too vigorous cleaning - the 2 frames from the other drum, completely clear ... I cant see any difference between drums, but I did process them sequentially using the same soup ... Anyway, perhaps a bit off topic, but rib related I guess.
Jason...has anyone actually USED the new Pyro developer from Gordon? I have been watching for some discussions of the developer here, and have noted very little if any written about MaxPyro.
Sorry to get a bit off topic....
i don't believe the faster oxidation is the "primary" cause of the base side ridge marks. This has been observed with non-staining developers, D76 for example, and apparently is caused by the developer speeding up as it crosses over the ridge. This gives more energy.
Originally Posted by nick mulder
However, pyro staining developers may accentuate the problem with some films that have a heavy gelatin coating on the base. If that is the case the ridge that results from agitation will be more pronounced from staining.
I'm going to try more developer volume (this should help with capacity/oxidation issues also), less strong concentration and slower agitation - looking back at the worst neg its most noticeable in the ridges that run side by side of the centre ridge (which splits half and half for 8x10") - I don't use these ridges for any of the formats I shoot so I might remove them also - they are for 5x7" and ?? damn, hang on, they'd be used for the 14" of 11x14" huh ... 8"x2 = 16" round minus 1" either side = 14" ... with a nice big ridge mark right down the middle to look forward to ...
Is everyone pre-soaking the film before adding the developer? The instructions that come with our Rollo Pyro kit recommend spinning a weak solution of sodium metaborate in the drum for about 3 minutes, dumping it, then adding the developer. We found that the old Bergger BPF-200 really had issues with streaking if you didn't do this, and the modern Ilford films are sometimes prone to streaking as well.
Just in water - I was using the Foma 200 film at the time but I haven't tried any other film in the Jobo yet with the PMK... I have FP4, Efke something and Arista Ultra Edu to try next ...
Are we talking about the same ridge issue tho ?