View Full Version : Understanding TMAX RS

brian steinberger
7-Feb-2005, 22:23
I asked this question before, but didn't fully understand. I'm using TMAX RS developer with TMAX 100 film. I'm developing in tanks and using hangers for 4x5 film. The tanks use a half a gallon of solution. What is the easiest way to get the most life out of a RS mix of one gallon? Should be replenishing, or using RS as a one-shot developer? I know that I need to mix 1:4, but if I did that then I would get no life from the developer. One gallon of solution would give me two runs, since I'm using a half gallon per run. Any help is appreciated!! Thanks!

8-Feb-2005, 08:54
Hi, the first thought that came to my mind when reading your post was that, are you developing enough sheets of 4x5 at one time to justify using a half gallon of developer?

8-Feb-2005, 10:59
replenished would be most cost effective. a half gallon tank means you're only running 12 hangers at most--probably more like 8 in a run? as a replenished developer, you can put about 300 sheets of 4x5 or more through a gallon of working TMAX RS, to dump it after a single run is just a waste. Even if you ran only a 100 sheets through it, you could still get about 4-6 months out of a gallon of it if you store it closed up well. If you left in the tank, with a floating lid, you can get about 4 to 6 weeks.

I use it in a larger tank at work in a deeptank line, and we don;t run film every day, but we will run about 350+ sheets of 4x5 through the tank before dumping it and this a *low* volume for a tankline. I dump at 4-6 weeks and even at the busiest of times, we only hit maybe 60% or so of the capacity for the developer. I like to dump & mix on a monthly schedule though, or as close to it given the holidays. What I'm saying is--you can reuse it. It's easy to replenish--uses the same chemistry, albeit another gallon to mix up & work with. You can't overreplenish & mess up the balance. You'll have to run hundreds of sheets through it to even put a dent in it.

Jon Shiu
8-Feb-2005, 12:07
Yes, you can just pour it back in the bottle and reuse it for 6 months or so. Builds up a kind of sludgy black color though, so might be good to filter it now and then.

Richard Abrahamsson
8-Feb-2005, 12:17
Can I use smaller volumes of working solution Tmax RS and just replenish that volume?

I have a Combiplan tank for 4x5" that takes about one litre of chemicals to cover the film. Can I mix working solution just for that tank valume instead of a whole gallon and just replenish that smaller volume after a certain number of sheets ( I think I read somewhere to add 45ml working solution per 8x10" sheet developed)? I am a litle bit reluctant to mixing a whole gallon since I don't shoot that many sheets a month and the working solution may get old. Moreover, I have a container to store between 0.7 and 1.5 litres without airpockets but nothing similar for a whole gallon.

Sorry if this is stupid but I am new to large format photography and 1 litre of one-shot developer for each batch of six sheets (fewer for +/- development, I guess) seems expensive to me.

brian steinberger
8-Feb-2005, 12:23
So to start over fresh, I should mix up a gallon or TS, and then divide the gallon into two half gallons. I use one as my working solution, and use the other as my replenisher. Is this correct? If so, how do I know how much replenisher to add to my working solution each time? Thanks!

Jay DeFehr
8-Feb-2005, 16:08
Kodak's website has all of the pertinent info. TmaxRS is an excellent developer for replenished systems, and worth getting familiar with. Good luck.


Duane Polcou
9-Feb-2005, 00:19
Brian. In the 90's I was the technical Rep for Edwal Imaging which produced, among other things, Edwal FG-7 film developer. I did extensive tests with as many developers as I could

find (RS, HC-110, Rodinal, PMK, D-76, Formulary, Acu-1, et al) in order to rotary process T-Max 100 sheet film, as I truly loved the idea of utilizing readyload. FG-7 produced, without peer, the highest acutance negatives among the group. These tests were done for personal reasons, not for the sake of marketing propoganda. Alas, my relationship with them ended, but my love for the FG-7/TMX combination thrives. It is super economical as well. Just thought I'd pass it on.

9-Feb-2005, 11:06
kodak will tell you--to mix up two gallons. You'll have to get 2 bottles stock A/B. You mix up one as per the directions on the bottle and this becomes the working developer for your tank or whatever. The second one becomes the replenisher. Up to the point where you run some film through that working developer--there's no difference between the two. When you start using the working batch, the replenisher is just a fresh solution, unlike some other replenishers which aren't complete film developers (they lack restrainer). When you start running film--the working developer picks up bromide byproducts and crap from the process and this retards the strength of the developer. So--the replenisher is doing just that, bringing it back up to working strength...which will be close, but not the same as the fresh solution. You will lose a bit of speed, and if you go too far for too long---the speed will drop off, and you might have some other problems as well, but all in all TMAX RS is pretty easy to work with.

But yes---you can split it into 2 smaller amounts and just use it the same way. They'll tell you not to do this in the tech sheets, but I've done it at home using smaller tanks and it works the same way. XTOL works well like this as well, lasts forever almost too.

You need to add 45 ml per roll of 135/36 or the equivalent of an 8x10. This would be about 4 sheets of 4x5. It's not rocket science and you can't overdo it in RS, so you can just guesstimate this....There's a way to track it scientifically--running Kodak Control Strips and plotting the results much like you do in E6. But this is b/w, not E6--trust me, if you can read a negative by it's contrast--what you like to print with , then you can replenish it and eyeball the results. In practice--you want to add as little as needed to keep it going. You will lose maybe a third of a stop or so in speed over time, but you should be able to figure out a set of development times for normal, and figure out an EI for your film as well and you oughta be able to hold this pretty well for the life of the developer. To be safe--keep good records of what you run through it, and dump it early. At the upper end---when you use up all the replenisher--dump it and start over. Dump it regardless of how much you run when you hit 6 months. Keep the replenisher in smaller containers too to ward off oxidation. When you replenish---either take out the amount you'll add from the working tank & replace it, or if you've lost volume in the tank--add the replenisher to make it up. In the old days--or with other developers that use separate replenishers--this was much fussier to do and there's a fine balance to maintain or else you can really screw your film up. RS is almost foolproof in this regard.

Hope this makes sense--believe me, it's much easier to do this in b/w than it is in color.

Richard Abrahamsson
9-Feb-2005, 11:25
That's what I call an answer.

A million thanks, kthompsson! Now I'm confident enough to try. I got the developer/replenisher and combiplan tank today.

9-Feb-2005, 16:46
well, with the combi tank...never used one, but I know what it is...but if you work with a liter to begin with, and then take the remaining solution to be the replenisher? What I would do--would be to track on a simple log how much film (size) and how you run it (time & temp for future reference), along with the date you ran it. Since you're only using a liter...when you add that much to it in replenisher, or when you approach maybe 75% of the original working volume--that's the time to dump it out. If you keep on going--which is possible, but not what Kodak would recommend--you enter a certain limbo in replenishment. What you're doing is sorta nurturing along the developer in a way similar to what you might do in E6 if you were running a big tankline. You might have to get into varying the replenisher amounts--either aggressively increasing the amount to keep up with lower rates of film and vice versa, or you'd have to play around with the pH or the specific gravity if the developer was evaporating in the tank--which you can see if there's a crust forming on the edge of the tank & the level drops....

If you add more than the original amount--the liter--what you're doing is working with a "seasoned" developer really. One that has been chewed up already by the act of running film. When you start up the fresh tank--it's going to actually run a little hotter than it will as you start to run more film & begin replenishing. There's an old trick for this---basically cut your development time by about 10% or so for the first few runs and as the speed drops off in the developer, bring it back up to your "normal" time and THEN start replenishing. Start at the amount Kodak recommends--45ml in this case as the process runs more steady. If you don't want to do this--then that's okay, the film will just be a little contrasty until it all evens out. The workaround is to use E6 first developer starter and add this to the mix and then the developer is "seasoned"--ready to go. But really--it just runs more contrasty, and you can fix that in the print usually, unless your exposures are really bad to begin with. I usually start replenishing after thefirst or second run of film.

There are all sorts of personal methods --some people add the replenisher after the last run of the day, some add after each run. Some take out the amount & replace, others just pour in some arbitrary amount to fill a tank back up to a level. Whatever you do--develop a ritual and stick to it--do it the same way every time and keep notes.

Theoretically you should be able to keep on going. I've used XTOL like this, where I basically just kept turning the tank volume over with replenisher. If the tank started to run a bit off--I would dump half of it and refill with replenisher (which like RS is just more XTOL stock). Worked great..ran it for a over a year like that. You couldn't see the bottom of the tank though, it looked like gray mud. This is sort of a problem at a certain point--this sludge can get stirred up in the bottom of a tank and cause streaking/sprocket drag type patterns on your film from surging through reels and hangers and past clips...other than that though, the developers tend to take on a life of their own, and they can be very consistent.

One more thing...RS likes to run at 75 degrees F. Could be a problem with certain films other than the T-Max stuff, which will all run at about the exact same time. If you need to pull a film, and you're going to drop under 5 minutes--which is a real possibility even for a normal run of TX or PX--then you can add teeny amounts of 28% acetic acid to both the working tank and the replenisher. I don't have the schedule in front of me now, but it changes the pH and you can add about 10-20% more time to the developer. I've never had to do this, but I will say that RS is not the best developer in the world for some more traditional films. Works great for T-Max family films though.

that's all you'll ever need & want to know about replenishing TMAX RS, for sure, so I leave you to it. sorry for the excessively long posts, can't seem to explain it any other way.