Uneven development in skies

[Steve Hamley]

Gentlemen,

I've been getting uneven development in skies (high negative density) when tray developing 8x10 negatives in 8x10 trays (there's adequate size for the neg to lay flat, plus a little). So I thought I'd probe the "collective" about potential troubleshooting methods.

I'm using pyrocat-HD in GLYCOL 2:2:100 for Tri-X, 500 ml of solution at about 70 degrees, 30 seconds initial agitation followed by 10 seconds each minute. 500 ml will give me a solution depth of 3/8". The non-high density areas look good.

Now my pyrocat solution A and B are about 2 years old, and as a consequence there's a relatively large amount of air "headspace" in the bottle.

The usual suspects are old developer and not enough solution in the tray, so to troubleshoot, I'll try fresh developer, more developer, and maybe a different developer since I have some fresh PMK I was playing around with.

Any other ideas?

Thanks! Steve

[Robert Hughes]

I've gotten uneven development in skies before, due to insufficient agitation. Nowadays I stroke my (gloved) fingers lightly across the negative during development to ensure more even development of large areas.

[Jon Shiu]

Hi, you might want to try brush development.

Jon

[ic-racer]

Bigger trays might help.

[Frank Bagbey]

Are you sure that is the problem? If you use glass neg carriers, you could be getting a reflection of sorts that only occurs at certain magnifications that looks alot like the problem you are describing.

[Tony Karnezis]

Steve, I had the same problem until recently when Michael Smith corrected the problem in my work flow.

How do you transfer the negs from the presoak to the developer? One by one or all together? In my effort to prevent scratches on Efke PL100, I would transfer the batch of negs together in a stack from presoak into the developer. Now that I carefully transfer them one by one, I stopped having the problem.

If that's not the problem, what about your development method? I tray develop 8-8x10 negs at a time and shuffle them constantly, roughly every few seconds. I'm not sure how to calculate how much agitation each one gets since the agitation occurs when I pull the neg out from the bottom of the stack. You say you agitate each neg 10sec/min? Could you explain what you mean and how you agitate?

[Jan Pedersen]

I believe it is the (B) Potassium Carbonate that is to old. Your A part is fine in Glycol but i have had the B part go bad after a little over a year.
Try with a new mix of Potassium Carbonate.

[Tony Karnezis]

Jan, I didn't think Steve's developer was too old based on Sandy King's experience.

Stock B, a 75% sodium carbonate solution, is always mixed in water, even in the glycol kit where Solution A is mixed in glycol. My experience is that Stock B mixed in water has a shelf life of at least two or three years, which is why I suggested that it has an indefinite shelf life. I think that if it goes bad in a year or less it must have been contaminated.

Sandy King

Steve, is it possible you could have contaminated solution B?

[sanking]

I believe the uneven development is due to insufficient agitation, not old or contaminated solutions. The problem as described is not lack of development, but uneven development.

Agitation for ten seconds every minute is not enough with sheet film using the 2:2:100 dilution. This is a very energetic dilution and leaving the film in the solution without movement is almost sure to cause uneven development. I would suggest that you try a more dilute solution, say 1:1:100 and agitate the film vigorously for one minute at the beginning, and then for five seconds every thirty seconds.

In my own experience neither the A stock mixed in glycol or the 75% potassium carbonate B stock should have gone bad after two years. I have on hand solutions of three or four years old that are still working fine. And in any event your problem appears to be one caused by insufficient agitation, not old or contaminated chemicals.

Sandy King

[monsta]

bigger trays i reckon. on the neg, are the edges darker from the wave effect of the edges of the tray? cheers, john