pyrocat and streaking

[jimcostello]

Using the pre-packaged liquid Pyrocat HD, 300 ml of water to 3ml of solution A and solution B, I developed two negatives of Bergger 200 4x5 sheet film in a Jobo CPE 2, processor, 70 degrees F, 2 min prewash, 9 min dev, 2x30 sec water wash, 5 min fix, 15 min washing with water change each minute for 5 min, then every 2 minutes until done. The Jobo drum rotates almost continuously throughout.

The negatives are very sharp but there is oblique streaking on both negatives, with one vertical streak on one negative. One negative is much worse than the other.

Any suggestions? I have never had streaking before with PMK pyro or other developers, however my prewash times were always at least 5 minutes. I used 2 minutes based on the circular that came with the developer. Is that my problem?

Thank you

 

[JBrunner]

It sounds to me like your agitation is too uniform, or you need to increase the volume of developer, or both. I water roll my home made tubes, and that gives a bit of a random wobble that is said to help with even development. Thats where I would start, but I'm sure others with more experience will contribute.

Welcome to APUG BTW

 

[agGNOME]

Can you post a scan showing the streaks? I haven't worked with the same variables such as a the same jobo model/dev./ film, but I've had issues with streaking and a jobo before. Particularly on 120/220. It was difficult to pin down the cause. This will go against logic, but what actually worked was leaving out the prewash and lowering the rotation speed.

 

[jimcostello]

It sounds to me like your agitation is too uniform, or you need to increase the volume of developer, or both. I water roll my home made tubes, and that gives a bit of a random wobble that is said to help with even development. Thats where I would start, but I'm sure others with more experience will contribute.

Welcome to APUG BTW

Thank you!

I used 300 ml. The minimum for the drum is 270 ml. The tank actually stops rotating for a second, then reverses direction. What is interesting is that I have developed negatives using HC 110 and PMK Pyro and never had this problem. I have never changed the rotation speed.

 

[jimcostello]

Can you post a scan showing the streaks? I haven't worked with the same variables such as a the same jobo model/dev./ film, but I've had issues with streaking and a jobo before. Particularly on 120/220. It was difficult to pin down the cause. This will go against logic, but what actually worked was leaving out the prewash and lowering the rotation speed.

I am afraid I don’t have a scanner. (

 

[Donald Miller]

I presoak for five minutes using Pyrocat.

 

[jimcostello]

I will try that with my next negatives.

Thank you.