View Full Version : Processing times for 4x5 in unicolor type drums?

Darin Cozine
19-Mar-2004, 14:18
Ive heard that Jobo tanks require you to change the developing times to compensate for continuous development. But I am using a Unicolor type drum processor.. Do I need to change the development times? Can anyone give me a rough guide as to how much?

Darin Cozine
19-Mar-2004, 14:27
FP4+ @ iso 125
Rodinol 1:50
20deg C

19-Mar-2004, 14:38

In short it depends. Test it out.

Bob Fowler
19-Mar-2004, 16:46
As has been said, test, test, test. FWIW - I get good results with Plus-X shot at normal speed (iso 125), processed in HC110 dil H for 8 minutes @68F in a unidrum.

Darin Cozine
20-Mar-2004, 18:09
FYI, I found that Ilford suggests reducing development time by 'as much as 15%'

OK, now I just need to figure out how to get a proper exposure so I can verify proper development. ugh! so much to do... so many variables.

20-Mar-2004, 19:38

i just dug up the instructions for a unicolor drum processor. they suggest the 15% as a starting point too.

good luck!

tim atherton
20-Mar-2004, 22:20
But - if you do a 5 minute presoak you will probably find your " normal" processing times are okay with no need for adjustment.

This is what Jobo suggests and I've found it's pretty much true for Unicolors etc too (unless you are using Xtol, when Kodak has tested times for rotary as well)

20-Mar-2004, 22:25
I've now developed about a half dozen 8x10 negatives in an 8x10 Western print drum run on a unicolor motor base. I use fp4 and d76 1:1, no presoak, fixed in the drum.

I have to admit that I've had some temperature problems and using "old" developer. These would normally indicate a longer development. But I searched for proper development times also, saw the "15%" suggestion and tried it. So far it looks about right. With what I'm using, new developer may even call for more, but we'll see what my new thermometer says about that ;-)

Darin Cozine
25-Mar-2004, 09:04
FYI, I ended up using 15 minutes with no presoak.