Developing sheet film in patterson orbital processor

[jimbobs]

Hi,I Have no problem developing 7"x5" HP5 Sheet film in this processor but when I do 10"x8" HP5 Sheet film in here I seem to get light marks on the neg, I pre-soak the film even though Ilford say you can get uneven developing marks on the film. I do the same with 7"x5" with perfect results, I was wondering if I have got a faulty box of 10"x8" film ?

[Tim Meisburger]

I used use just 70ml of liquid in mine to develop Shanghai, and thought all those people who complained about uneven development with minimal chemicals were just wrong. Then I switched from Shanghai to Ilford FP4 and immediately started getting uneven development. I cut the fins off (if you leave the fins on with more than 100ml or so the fluid hits them and you get swirl marks) and started using about 200 ml of developer and since then have had no problem with uneven development. Are you using minimal chemicals? Maybe the uneven development is just more visible on the larger negative?

[Jim Noel]

I used use just 70ml of liquid in mine to develop Shanghai, and thought all those people who complained about uneven development with minimal chemicals were just wrong. Then I switched from Shanghai to Ilford FP4 and immediately started getting uneven development. I cut the fins off (if you leave the fins on with more than 100ml or so the fluid hits them and you get swirl marks) and started using about 200 ml of developer and since then have had no problem with uneven development. Are you using minimal chemicals? Maybe the uneven development is just more visible on the larger negative?

YOu don't say what size film, or how many at a time, or dilution of developer, but it really doesn't matter - you have insufficient developing agent available.
Trying to save money by skimping on the quantity of developer is not a wise decision.

[jimbobs]

Thanks for both replies to this,yes as I say I use the Orbital Processor without the fins in and use onlu 200 mil of developer. As I said before don't have any issue with 7"x5" just the 10"x8",will try another pack of HP5 and see, thanks for that