Time of HP-5 in Xtol with Jobo Processing

greenspun.com : LUSENET : Large format photography : One Thread

I have been doing zone system testing with HP-5 in Xtol 1:1 in a Jobo processor. My time for normal development with zone VIII at 1.30 density is 12 min. at 70 degrees. This time is 50% greater than the time published by Kodak, which makes me wonder if I have done something wrong. Has anyone else had a similar experience with HP-5, Xtol, and Jobo processing?

-- William Marderness (wmarderness@hotmail.com), January 05, 2000


I'm not positive about this but aren't the Kodak figures for rotary processing shorter than their times for processing in tanks? In other words, Kodak suggests a shorter development time to compensate for the constant agitation of a rotary processing system. Jobo, on the other hand, recommends a 5 minute presoak and about the same time as normal i.e., the long presoak serves to compensate for the constant agitation of rotary processing. So if you did use the presoak as per Jobo's recommendations, your times are likely to be longer than the Kodak recommendation. In any case, its a moot point, as long as you get the densities you want on the negative. Hope this helps. DJ

-- N Dhananjay (ndhanu@umich.edu), January 06, 2000.

If you don't use a presoak the time for continuous agitation will be shorter than for intermittent agitation; if you use a presoak it'll be the same or longer.

The only thing that counts is your results.

FWIW, my time for HP5+ in Xtol 1:1, intermittent agitation, is 10'30"/70F, EI 400, Zone I at .10 DU above fb&f, Zone VIII at 1.37 DU.

-- John Hicks (jbh@magicnet.net), January 06, 2000.

Moderation questions? read the FAQ