TMAX RS dilution

[brian steinberger]

I just bought my first set of chemicals for processing TMAX100 in my darkroom. I mixed them already, but am confused about the Tmax RS developer. I mixed the whole gallon. Am I just supposed to use that as is, and reuse everytime? Or should I be diluting that gallon solution even further? My friend told me to mix a batch diluted 1:4 evertime I process a new batch and then throw it out. Help me! I'm axious to start processing.

[brian steinberger]

by the way, i'm processing 4x5 film in small tanks using hangers.

[Tom Westbrook]

Can you go into more detail about what size of RS you bought and how you mixed it. I'm not clear on whether you bought the gallon size or the quart size of the concentrate from the store. Also, how did you mix it? With water or did you just add the Part B solution?

[Michael Kadillak]

Mixing the batch as instructed to get a whole gallon while also adding part "B" is the standard 4:1 dilution. It is perfectly acceptable to develop at this strength. Just look at the recommended time tables. To get to 9:1, just mix the 4:1 with equal parts of water and that will lengthen your developing times.

The only thing you should be concerned about is that mixing it with water decreases the time that it is usable to about 1-2 months. John Sexton is the resident expert on T Max emulsions and the RS developer. I have read that he puts the Part B in the Part A concentrate bottle and just mixes what he wants from concentrate 4:1 or his preference 9:1. Developer last a whole lot longer.

T Max 100 is noted for being fickle about consistent agitation although it produces fine grain and excellent expansion and contraction and reciprocity characteristics. JOBO rotary processing provides excellent results with this fim albeit at a price. JOBO processors are not cheap. If the hangers give you a hard time, you can try rotary development in cheap PVC tubes or the Beyond the Zone System tube processing system. This subject has been discussed extensively here.

Cheers!

[brian steinberger]

I mixed the whole gallon. And I'm reusing it after each use. I did it yesterday and the negatives look great. But if next time I buy RS I mix just the part B into the Part A bottle and work from that, mixing at 1:4, should I just throw out the developer after each batch? or should I just keep doing what I'm doing now mix the whole gallon and just reuse it?

[Michael Kadillak]

In all of the literature and discussion of this subject I have been privy to, it was always advised that it is a one shot developer. Use it once and toss it are my recommendations.

The degredation of the negatives with continued use may be hard to see and IMHO, it is not worth the risk considering the investment in film and your time.

Cheers!

[brian steinberger]

So next time I want to do like John Sexton does and mix part B into the part A bottle and leave that as my stock. Then when I'm ready to develop I mix 1:4 with water and that is my working solution. After I'm finished I discard. Is this correct? How many negatives can I run through one batch? Thanks alot for all your help!

[Michael Kadillak]

Yes Brian, that is correct. Use this composite A&B as your stock to be mixed. You might also try 1:9 to get some additional mileage out of your developer. Development times are longer, but still great results. Sexton uses this dilution as well. I do not know the exact unit of film per developer ratios from Kodak, but it is not important. Fill your developing tank and make one run with it (how many hangers you can get in one tank is "one" run). Dump it and use fresh developer for the next.

Good Luck!

[brian steinberger]

Michael, so if I mix 1:9 then my develop times are twice as long as 1:4 correct? Thanks

[Michael Kadillak]

Not necessarily. Go to the Kodak website and look at their recommended starting times and temps for this dilution and start from there. Modify as necessary after you inspect your results.

Shadows are dictated by exposure, but should contain detail (unless you are purposefully taking it out). Highlights are driven by development time.

Cheers!

[kthompson]

brian--if you mix it (RS) up as a gallon as the directions on the bottle tell you to do. Which is to take that quart of A and mix it in with a half gallon of water and then add the packet of B to it while slowly stirring and then top off with water to make 1 gallon. This gallon becomes the working solution. If you wanted to reuse it--then simply buy another bottle of A/B and mix that up the same way, but split it into some smaller containers, unless you run a ton of film in a short amount of time. This second batch of RS becomes your "replenisher". The replenisher will last for months if it's sealed up properly.

Another way to do it--which works---is to split the mixed gallon into two half-gallon containers. One becomes the "working" developer--what you use in your tanks with the 4x5 hangers (which is probably a half gallon hard rubber or plastic tank). The remaining half becomes the replenisher. If you do it this way--roughly halve the capacities that Kodak gives you.

A gallon of RS--as a replenished solution in a tank with a floating lid will run for 4-6 weeks if you treat it right. You can run 320 sheets of 4x5 film (80 8x10 equivalent) per gallon replenished--IF--you add 45ml or less for every 4 sheets. Do your first run or two with the developer unreplenished. Take about 10% or so off the "normal" time you would usually use, and then as the contrast starts to drop on the negs, adjust the time back to the normal and start replenishing at the rate Kodak gives you and adjust according to how you prefer the contrast of your negs. You will never be able to overdo it with RS--like you can with D76/D76R--you use the same chemistry to replenish with--albeit as a fresh soln, and not "seasoned" like what happens with the working developer. The working developer will last longer if you drain the tank into a closed jug--you can get about 6 months tops out of it. Usually what you do is to dump it in when you add the same amount of replenisher to it, or when the time for the tank is up. In practice, it actually helps to dump it a little early.

TMX likes to run at 75 degrees in a tank this way--a good normal time should be about 6 to 7 minutes. I've run a deeptank line where I work for about ten years now using RS like this, running mainly 4x5 TMX. It works great, it's a very clean, easy to use replenished developer. It's a waste of money to use it one-shot for a tank, but that's just my opinion. Good luck & hope this makes sense. Kodak has tech sheets for replenishing if you're interested.

[brian steinberger]

If I split my gallon now into two half gallons, how do I know how much replenisher to add to my working stock after each session?

[kthompson]

You can't really do it at this point if you've alreay run film through it. You would do that when you mix up fresh. Right now--depending on how many sheets you ran through it--you have a slightly used developer. I'll bet you can keep on running film through it and get maybe even 25-30 sheets of 4x5 through before you even see a decrease in contrast and/or speed. I would just chalk this first gallon up to reuse with extended time added for additional runs if needed--OR--I'd go buy another gallon of it to mix up for the replenisher. Then again--there is a chance, say if you ran only 2 sheets or something miniscule through it--that it wouldn't matter that much. Technically it's not a replenisher really at this point, but TMAX RS is a pretty strong developer straight--it tends to be very punchy, runs hot. I think you'd be surprised how much film you can run through it as a replenished developer--you may wind up losing about a third to half stop in speed eventually, and the developer will take on a slightly murky look that can look bad if you're used to some crystal clear soln., but this is pretty much where you want to be with a seasoned developer.

Kodak probably has some specs on adding time for reuse, but I've never used it any way other than as a replenished developer.

[brian steinberger]

Ok, well I'll run many more sheets through the solution I have now and eventually I'll just throw it all out and start over. but when I start over and mix the gallon and split it into two half gallons, how do I know how much replenisher to put into my working solution after a session?