View Full Version : jobo 4x5 reel and tank, unicolor motor base

Gray Mitchell
5-May-2005, 19:57
I am developing my negs with a 4x5 reel and jobo tank on a unicolor motor base. shooting mostly tmax 100. havent dont film tests yet, just wondering if anyone is using this system and if so, what are your approx. Normal and N+/N- times. i am assuming normal dev. would be less due to the constant and speedy agitation. Also, has anyone noticed that this kind of tank development on a motor base increases contrast? thanks

Eric Biggerstaff
5-May-2005, 20:23
What developer are you using, what dilution and at what temp?

Gray Mitchell
5-May-2005, 21:02
oh yeah, i guess that would help...sorry about that. i use D-76 1:1 @68 degrees. i also use Ilfosol-S 1:9 @ 68.

Eric Biggerstaff
5-May-2005, 21:39
A good starting point for rotary processing it to take 10% off the suggested time for your developer for normal. Then for minus one (-1) take another 20% off, and for plus one add 20% to your normal. It is tough to say without film testing however.

Here are the times a VERY well known landscape photographer uses for T-Max 100 rated at 64 (if I remember his rating correctly) using D-76 developed in a Jobo:

Normal = 9 minutes
Normal Minus 1 = 7 minutes
Normal Plus 1 = 11.5 minutes

Always use FRESH D-76, fresh being mixed no more than a week before use. Older D-76 will increase contrast, also there is a slight increase in contrast due to the rotary processing.

Hope this helps.


Gem Singer
6-May-2005, 03:16
Hi Gray,

Click on the red words "Large Format Photography Home Page" near the top of this page. Scroll down to "Traditional Processing and Printing". Click on John Sexton's article entitled "A Few Ideas on Using Kodak T-Max Film Successfully". The information contained in that article will answer most of your questions.