Jobo processing & contrast

[Warren Williams]

I have a CPE but have been hesitant to use it for sheet or roll film development because I have always heard that constant agitation leads to contrast build up. Most of my photos are of high contrast subjects anyway (lots of architecture in bright sunlight) so the additional theoretical contrast would be very unwelcome. I have been using a HP Combi but the negs keep slipping out of their slots and end up touching other negs and leaving marks so I am looking for an alternative.

[Jim Noel]

Don't be overly concerned about the contrast build up.
Reduce your development time by 20-25% as a starting point.
Upon inspectionof the dry negatives you may wish to further reduce the developmen time a little more, or you may find you need to reduce it a little less. 20-25% usually works for my students.
Variable contrast paper will be a big help in ending up with a print of appropriate contrast.
Jim

[Ron Marshall]

My N-2 negatives develop nicely in the Jobo 3010, using D76 1:1. But I did development tests to determine the correct times with my system for N-2 to N+2.

My times are much shorter than I was using in the Combi.

[Warren Williams]

Thanks for the responses. I was under the impression that intermittent development allowed some compensating action as the heavily exposed areas slowed down the developer adjacent to them and the developer worked more on the lightly exposed areas. Is this effect overstated?

[Bruce Watson]

Thanks for the responses. I was under the impression that intermittent development allowed some compensating action as the heavily exposed areas slowed down the developer adjacent to them and the developer worked more on the lightly exposed areas. Is this effect overstated?

IMHO, there is little to no compensation action with normal intermittent agitation. You get compensation through developer starvation which implies stand development.

[Tom Perkins]

My experience is consistent with what has already been posted. Here is an article by John Hicks on the Unblinking Eye website: http://unblinkingeye.com/Articles/Rotary/rotary.html