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scott palmer
23-May-2016, 13:07
I'm getting hot, over-developed edges on my tray-processed sheet film. It's consistent and significant, making the negatives difficult to print evenly. I use PMK pyro on Ilford HP 5, with constant agitation for six sheets a batch. I'm going to guess it's from agitation, but I'm not doing anything unusual when I process. Has anyone else encountered this problem and resolved it? If so, how? Any thoughts would be greatly appreciated.

koraks
23-May-2016, 13:36
I run into it from time to time with xray film, but in my case, the cause appears to be density buildup on the bottom side of the film as fresh developer gets to the surface along the edges but not in the middle
Flipping the sheet over frequently usually solves it.

I read in other places that using a larger tray should help, as it prevents the issue of developer bouncing against the edges and thereby resulting in increased agitation along the edges of the sheet. I can't comment as Ive never tested this specifically.

MartinP
23-May-2016, 14:32
If you have just a few sheets at a time to develop you could make yourself a slosher. The basket stops the film accelerating and decelerating quite so much near the edges of the tray, agitation being by tilting or draining. It doesn't help if you have dozens of sheets to process though, as it would take ages doing them four at a time.

jp
23-May-2016, 14:41
I have fixed this by using a bigger tray. Extra turbulence/interference at the edges from waves bouncing off the tray walls and back into the negative.

BetterSense
23-May-2016, 20:38
I also think bigger tray and deeper developer helps. I develop 4x5 in 8x10 trays with a least 1 liter of developer.

Doremus Scudder
24-May-2016, 00:20
I develop 4x5 in Paterson 5x7 trays and use PMK, 500ml per tray. I like the Paterson trays because they are deeper and smooth.

I've had the "hot edge" issue when pushing the sheets too quickly down into the developer when agitating. This caused the developer to swirl up around the edges increasing edge density of the negative. The solution was to simply not push the negatives down into the solution so aggressively.

FWIW, my agitation technique: after a water pre-soak, I fan the sheets in my hand and immerse them emulsion-side-up one-by-one into the developer, giving each a gentle lift-and-drop agitation along the way. The interval of the immersion depends on the number of sheets; I evenly space them over 30 seconds, e.g., if I have 6 sheets, one is immersed every five seconds, for 5 sheets every 6 seconds, etc. After the initial immersion I then shuffle the sheets from the bottom of the stack along the short axis, turning each sheet 180 each time. I shuffle once through the stack every 30 seconds for the first half of development (same intervals as the initial immersion) and once through every 60 seconds for the second half of immersion. All the time I keep track of sheet one to make sure it ends up at the bottom of the stack at the end of development. When time is up, I collect the stack, fan it like a hand of cards again and immerse the sheets one-at-a-time in the stop.

The main thing to watch out for if you have hot edges is to gently guide the sheet down to the bottom of the solution; not push down hard on the center of the sheet.

Hope this helps,

Doremus

John Layton
24-May-2016, 08:38
After an extremely gently-agitated pre-soak (water with a few drops of Photoflo) in a single 8x10 tray...the six 5x7's are each placed, in sequence, into their own, individual 5x7 trays, each with 10oz of (pyrocat-hd) developer. The six 5x7 trays are placed in two rows inside a single 20x24 tray - and the larger tray is gently rocked in all directions during agitation cycles. Following development, the films are (in sequence) placed into a single 8x10 tray of weak stop, then water, then fix, etc.

I've found the above "hybrid" procedure, using individual trays during the very critical development step, to have successfully addressed whatever issues of uneven development that I may have had previous to this.

Peter Lewin
25-May-2016, 17:54
I was thinking about Doremus's post while I tray developed some sheet film today. He mentioned keeping track of the first sheet he immersed in the developer, presumably by keeping count. While I also keep count, I rotate the last sheet in by 180 degrees, so for example if all the other sheets have the notches at the top, the last sheet I put into developer has its notches at the bottom. That way if I get distracted during the shuffling, I can always tell by feel when that final sheet is on top of the stack, meaning that sheet number one, the first to go in. and the first to come out, is on the bottom.

Jac@stafford.net
25-May-2016, 18:05
Has anyone used Honeywell Nikor 'rocking canoe' tray development?
.

Willie
26-May-2016, 20:08
Trays too small. If you want to stay with the trays and get rid of the extra density try brush development. You gently waft a brush side to side, then up and down. Then repeat going the same or opposite direction. Gently and evenly the whole time.
Clean and even development. The Richardson Magic Brush works well as do Hake brushes you have worked a bit so they don't shed.