TMAX 100 in XTOL 1:1 Jobo Expert

[Paul Butzi]

Kodak (at www.kodak.com/global/en/professional/support/techPubs/f4016/f4016.jhtml?id=0.1.18.14.23.18.16&lc=en#rotary-tubeprocessing—rollsandsheets) list the development time for TMX in XTOL 1+1, rotary processing, as 9 minutes at 70f, 7.75 minutes at 75f.

If I wanted to find a starting point for 70f, in my darkroom, I'd take my 75F time (6.8 minutes) and scale it using the Kodak numbers - that is, I'd multiply my 6.8 minute time by (9/7.75).

The result (according to Excel) is 7.9 minutes.

It would be worth doing your own development testing - with good estimates for the times, it really only takes three development runs to get completely dialed in.

[ronald moravec]

I can`t help with times except to suggest you do some tests of your house, car, dog or whatever before you commit good film to an unknown process.

Next make sure you use enough stock developer so it doesn`t poop out before the end of the cycle. 4 oz of stock for 4/5 sheets is about right. That makes it difficult to do 10 sheets with the 270/300 cc total allowed.

[Paul Butzi]

I don't know where Ronald got the 270/300 ml figures for the 3010 drum, but they're wrong.

I have been told directly by the staff at Jobo that the minimum solution volume for the 3010 is 210ml (which is what is on the label on the drum) and the maximum is 1 liter.

Kodak list the capacity of XTOL as 100 ml of full strength developer for every 80 square inches of film to be developed. (Don't blame me, that's the way they list it, complete with the mix of metric and english measurements).

Four sheets of 4x5 is 80 sq. in. The drum holds 10 sheets, for a total of 200 square inches, so we need 250 ml of stock solution in the drum to run 10 sheets.

If we're diluting 1+1, that means we need 500ml of diluted developer, which falls comfortably between the 210ml minimum and the 1000ml maximum for the 3010 drum.

[ronald moravec]

My recommended volumes came on the instructions furnished with the drum when I bought it.
I also have a bound book with similar volumn recommendations. It was written about 20 years ago.

I have heard of others using using high volumns, but then the drum gets very heavy putting a lot of stress on the machine.

Perhaps Jobo has changed their recomendations?

[Oren Grad]

Ronald, if you go here and scroll down a bit, you'll see a table in which Jobo clearly specifies minimum and maximum solution quantities for the Expert drums.

That said, my impression in actual use has been that the motor strains pretty visibly when the volumes get above 600ml or so in the larger drums (e.g., 3005), so I don't ever go that far. (Yes, my CPA-2 is late enough to have the most recent motor hardware.) I think 500ml in a 3010 should be fine.