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While testing a number of 35mm films dev. in Pyrocat HD (kit from Phot. Formulary) I noticed a significant density variation corresponding to the area between the sprocket holes (darker band protruding into image area from edge). I've not seen processing artifact for many years.
I'm using a Jobo CPA-2 on the very slowest rotation I can set, a double-reel in a 2523 tank and 306 mls of solution. (3+3+300)
[process: 5 min D/W presoak, 8 - 13 min. dev time, 30-60s stop (Ilford's citric acid bath at ~1/3 strength), two bath fix, rapid fix, no hardener, 2 min. each, water rinse, Permawash, final wash. All except final wash in Jobo tank at slowest rotation]
Have any of you others found this problem with Pyrocat and 35mm? Solutions, more developer, slower rotation (somehow...)?? (I've not noticed this recently with my normal XTOL (1+3) - have not used Pyrocat on any larger formats yet).
Dave
(testing Across 100, Tri-X, Delta 400, HP5+ and Neopan 400)
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Dave,
I have never developed 35mm film in a Jobo CP-A but the cause of extra density at the edges of the film, accompanied by the streaks at the performations you describe, is almost always due to *overagitation." So the only solution I could suggest is slow down the rotation if possible.
But not to skip over the problem, coinsider developing your 35mm and roll film on reels in inversion tanks with minimal agitation. I see a real big difference in apparent sharpness in 35mm and 120 size with this type of development compared to rotary.
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Thanks for your observations Sandy. Overagitation was my first thought. The Jobo is a slow as it will go (by dial setting anyhow - it's jammed against the switch detent).
(aside - does anybody know any "electronics" tricks to alter the motor speed controller to get a slower rate, without stalling the motor???)
I will be resorting to my old SS reels and invertible tanks for the rest of my 35mm testing. (was getting lazy and thought I'd try the Jobo for 35...guess I know better now.)
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 Originally Posted by Dave Swinnard
The Jobo is a slow as it will go (by dial setting anyhow - it's jammed against the switch detent).
Strange ... If I turn the "Rotation" switch below the slowest setting, the motor turns off.
I've developed a **bunch** of 35mm with mine - and have had *NO* problems ... but that was not with Pyrocat HD.
Any way to scan the negatives and post the images?
Carpe erratum!!
Ed Sukach, FFP.
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There would possibly be a lot of tricks to slow it down.
But since I've never seen one or it's diagram, at this moment I cannot help.
If you ara able to get more data, let me know.
Jorge O
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Only thing I can think of to slow it down, aside from a makeshift brake, would be a rheostat.
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A rheostat could do, but it could become quite hot.
I think (?) it possibly uses an simple electronic control akin to the ones used in power drills, etc.
But as I've said, I need more data.
Jorge O
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In my Jobo, I develop 35mm tri-x in pyrocat, mixed 10ml each of solutions A & B to 500 ml of water for 6 to 9 min at 68 F, with a rotation speed of "3". I presoak for 5 min. I use a plastic jobo reel,i think 2502 (i'm not home, can't check) I've noticed no problems with uneven development around the sprocket holes.
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It came to me that perhaps the rotation was "too slow" and the developer flow was too smooth so as to cause a non-random flow around the sprocket holes. (one of those early morning, why am I not sleeping brainwaves)
Since I've not had any problems with 35mm films and other developers in the past while using Jobo at the 75rpm setting (yes, I calibrated the various settings when I purchased the used processor...) and only with Pyrocat HD and the slow (~28rpm) setting, I thought I'd try a roll at each setting. Will update tomorrow when last roll is dry and contacts made. (looking for agitation artifacts and increase in general fog / stain level)
Dave
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I process 35mm, 120 and 4x5 with my Jobo CPE2 Plus. It has only one speed which is around 75 rpm and have never had any problems. I give a 2 minute presoak before development. I have used D76, D76H, D23, XTOL, PMK Pyro and PyroCat and no problems with either uneven density or sprocket surge problems.
- Mike
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