PMK Pyro streaks in Jobo - Pyrocat-HD/Rollo solution ?

[nick mulder]

Efke 11x14" and Arista Edu 200 8x10", PMK+EDTA, pre-wet tubes, occasional lateral agitation, increased amount of chems...

Base side streaks - cant be seen on either of the negs, but bang there they are in the prints

I'm back to trays at midnight until I can try some Pyrocat-HD

 

[damonff]

Streaks and high b+f was reported in the very early days of PMK. The main issue is tht the developer oxidizes very rapidly. Solutions offered have been, 1) splitting the total volume of developer, discarding half of it at the mid-way point and adding the fresh, 2) adding a bit of sulfite to the working solution, or 3) adding some ascorbic acid to the working solution.

All of these methods work, but Rollo Pyro and Pyrocat-HD and -MC work equally well without any of the above remedies and give results that are just as good as.

The stain from the ridge marks is another issue, and is caused by agitation. It can be reduced or eliminated by, 1) using a much weaker dilution of the developer, with extended development time to compensate, or by 2) slowing down the rotation of the drum in RPM, or 3) by both 1 and 2.

Sandy King

I used a 1:2:250 dilution today and did a 30 minute semi-stand, agitating for the first minute and then at 15 minutes. No streaks. I love the results. It was with Foma 200 shot at ei 125.

 

[Rick Olson]

Hi Nick,

I develop my 8 x 20 negatives in a 16 x 20 drum, using Pyrocat-HD by hand. Machine rotation caused too many problems. My solution to perfect negatives every time (using some of Sandy's tips):

I have crafted/cut an acetate sleeve that is inserted into and covers all of the ribs in the drum.
I only develop one sheet of 8 x 20 at a time.
I use 2 liters of fresh developer per sheet.
Rotation is by hand and slow at 4-5 revolutions per minute, with reversal of direction and gentle tilting.

Good luck!
Rick