Development times using Jobo Expert Drum

[Mark Lipton]

I will be developing 4x5 T-Max 100 sheet film (exposed at a speed rating of 64)i n a Jobo 3006 Expert Drum with a Uniroller base. I would appreciate some recomm endations from anyone who has used this setup as to appropriate development time s and temperature for a range of N-3 through N+3. Developer will be T-Max RS d iluted 1:9. Thanks for your help.

[Stewart Ethier]

I was at Anderson Ranch last year and found a sheet there with the following recommendations for developing T-Max 100 sheet film, using T-Max RS developer at 23.9 degrees C, or 75 degrees F. They assume a Jobo processor with speed set at 4.

N+2, 12.5 min., 1:9, EI 100

N+1, 9.5 min., 1:9, EI 80

N, 7.0 min., 1:9, EI 64

N-1, 5.5 min., 1:9, EI 50

N-2, 5.0 min., 1:11, EI 40

I haven't tried these myself, but I have used the corresponding recommendations for T-Max 400, which are similar, and they seem to work well.

[Tim Kimbler]

Try the JOBO home page. I use the same set up your using. I follow their recomendations. TMAX dose good for me, but I get better results with TRIX. I use XTOL 1to1 developer.

[Christopher Cline]

Hi Mark

I use a 3006 Expert Drum with a CPA-2 set to a 3 1/2 rotation speed. I develop in T-Max RS @ 24 degrees Celsius with a 5 minute water presoak. I got the times I use from Don Kirby and Stu Levy, and they work very well for me. My dilutions are made straight from the syrup concentrate (with the B packet poured into the concentrate bottle). 1+9 dilution for me means 1 part syrup concentrate plus 9 parts water.

Development Dilution Time

N-2 1+19 14m 0s

N-1 1+9 8m 30s

N 1+9 11m 30s

N+1 1+9 16m 0s

N+2 1+4 11m 0s

[Sal Santamaura]

When folks say they're using speed 3 1/2, what drum rpm does this represent on your machine? Jobo's Web site includes a page

http://www.jobo-usa.com/faq/CPP_Speed_Settings.html

which indicates that different rotational speeds result from the same settings depending on which motor is installed. I've asked Jobo directly about this because they have a Sexton article on their site that also recommends speed 3 1/2 which was written in 1994, possibly before the motor change. When they respond I'll post the answer here.

[Sal Santamaura]

I asked Jobo whether, based on their speed setting page (referenced in my above post), I should be using the "F" setting on my new CPA-2 to achieve the rotational speed Sexton was getting in 1994 by using 3 1/2. Jobo's answer is:

"Your analysis seems correct to me. The most important factor is the speed itself, not the printed marks on the speed dial. To determine the setting for 50 rpm's for YOUR processor, put the drum on the lift with water inside to simulate a typical chemical load. Swing the 3-fingered switch (behind the cog on the motor shaft) out of the way, so the motor will not reverse. (We only use the single direction for determining speed, never for real processing.) Set the speed dial to F and start a stop watch, and count the drum as it turns. If indeed your particular processor happens to run at 46 when set to F, that will be great! If it's a little farther from 50 rpm's, you might adjust the speed control and check its speed again until you are real close to 50. Then take a pencil and make a mark on your speed dial, and THAT is your setting for 50."