TMX/Jobo-which Dev?

[Jorge Gasteazoro]

Don, I have to disagree with you very strongly....1/10 of a degree? This is overkill, as a matter of fact T max is more sensitive to variations in agitation than it is to temperature. Back when I first got my densitometer I tested this. I plotted the different CI for T max developed from 70 to 78 F. The difference from one film to the next was very little, of course the difference between th 70 degree roll and the 78 degree roll was very great, but the rolls that only had one degree difference did not have a big change in contrast. What does make a big difference is agitation, this is a well known fact of T max films. If you wish to obtain the same results you need to agitate the same way. Although I agree with you that consistent darkroom practices will yield the best results, I am answering to your post because it this type of erroneous information that make beguinners paranoid and leads them to hate darkroom work! As a chemist I can tell you that 1/10 of a degree will not make a difference one way or another, give me a break! Althought there are many specialized chemical reactions that are dependent on rigorous temperature control, darkroom work is not the case.

[kthompson]

I agree with Jorge on this....I don't have any rotary tube experience with TMAX RS (I do with E6 though), but for the last 6 or 7 years, TMAX RS replenished has been our choice for the deep tank line. We run mainly TMAX 100, but will do batch runs of other films such as Ortho+, Tri-X, TMY etc. Our normal run is 7 min. at 75 degrees F for TMX. I agree that consistency (in everything: mixing, agitation etc.) is the key, but even with running waterjackets for the tanks, I've never experienced a 1/10 th degree sensitivity with any b&w developer.....even running daily control strips on E6, that process isn't THAT sensitive to minute temp changes....our Intellifaucet constantly cycles, calibrating the mix down to a tenth or so, but in the end, you have to have some really wild fluctuations to see a difference even in the plots. Of course, this could be more of a problem if you're using really dilute developers....we use RS straight in the tank, replenished. And our Wing-Lynch uses a heck of alot more chem. in it's trough than any Jobo does. Exhaustion is not a problem with those machines. I know that some people have figured out ways to dilute TMAX RS down & use it one-shot, but I think this developer really excels as a deep tank developer...used straight & replenished (as it was designed). In that capacity it's the cleanest working developer I've ever used.