Diluting TMax developer?

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I'm developing Tmax film in TMax-RS in BTZS tubes. The TMax-RS comes in a kit that makes 1 gallon of working solution. Has anyone tried diluting that working solution further for use in tubes?

Darkroom Inovations recommends tossing the developer after one use. With 2oz. used per 4x5 neg., that will yeild only 64 negatives per gallon of developer. For both economic and ecologic reasons, it seems like I should be able to extend that more, don't you think?

I'm still doing testing to find personal ASA numbers, so I can play around a bit with times and concentrations. Can you suggest any guidelines as to the ratio of dilution verses development time? If I dilute the developer by 50%, should I double the time? Or, are the Tmax films and developers just too sensitive to mess around like that?

Finally, how long do you keep your fixer for? If I'm only doing 5 or 6 negs, I hate to toss 16oz of fixer down the drain (which is what I've been doing). Should I poor that back into a bottle for reuse?

Thanks for your replies,

-- Douglas Gould (assistdelrey@earthlink.net), May 17, 2002


You probably can get by with diluting T-max RS developer by half. To be safe you should look up the Kodak minimum developer required for 80 sq. inches of film--the equal of one 36 exp. of 35mm, 1 8x10 or 4 4x5 sheets--then divide by 4 for individual sheets in tubes. Kodak will have this info on its web site.

As for processing times, you should be in the ballpark if you dilute by a factor of 2, then increase your time by 100%. With diluted developer, you will have a more gentle developer, so being a minute off, one way or the other, will not be very dramatic. You can fine tune to your needs from there.

You didn't say what fixer you use, but I use Photographer's Formulary TF-4, and I get the equivalent of 40 35mm rolls of film (or 160 4x5) per gallon of working solution. And that is conservative. I think you will find similar capacity from most commercial fixers, so certainly you do not need to discard it after each use. Just keep track of how many sheets you put through it.

-- Ted Kaufman (writercrmp@aol.com), May 17, 2002.

Besides keeping count... you can use a fixer tester. 2 drops in 2 ounces of fixer... if there's milky precipitation then it's exhausted.. the brand I use is Nacco...

-- dan n. (dan@egmail.com), May 17, 2002.

Why does "darkroom innovations" recommend using it as a one shot developer? Is there something about tubes that exhausts developer more quickly? RS is meant to be reused after each use after adding a small amount of fresh developer to "replenish" it to full strength. Why won't this work just as well in tubes. It works reliably and economically for me using tray development. If RS doesn't work as designed in tubes, you may want to consider moving to trays for the reasons you list. Good luck.

-- jimRyder (j.ryder@verizon.net), May 17, 2002.


I think you misunderstood: DI feels that because such a small amount of developer is used in tubes, one would get far more consistent results if one discards whatever developer dilution one is using. They don't say anything specific about TMax, but rather all developers in general.

The reason I don't use trays as you suggest is that I work in very limited spaces, like an RV, or on my 40' boat. I do not need a dark room to process negative when I use the tubes. I load the tubes in my Photoflex changing room, and I can carefully screw the tube caps filled with developer inside the changing room too.

I developed 12 negs just two days ago, and I never even turned out the lights....try that with trays!

Thanks for your reply though

-- Douglas Gould (assistdelrey@earthlink.net), May 17, 2002.

I plead ignorance but I thought something like that. Nevertheless, it seems possible to create a replenish schedule that would work with out diluting. For instance, I would start with lets say 16 oz of developer. Use about 5 oz for the first batch. Pour that back into the 16 oz container, pour out about 2 oz and add 2oz of fresh. while the 5 oz was completely used up it is mixed into 16 oz and only then replenished. In other words don't dilute but mix back into enough fresh developer and then replenish. I don't think tmax will work well diluted, but it works very well when almost exhausted developer is replenished. This may not work but something like this seems worth a try. And of course keep careful records of how much film you have developed. and test. Thanks for the suggestion I try tubes but I enjoy dark rooms. Again good luck.

-- j.ryder (j.ryder@verizon.net), May 17, 2002.

The BTZS tubes are intended for maximum control of individual exposures, along with the testing system. Dilution of TMax-RS, usually at 1:9, gives extended "toe" and shadow detail - far superior to full strength or even 1:4. "One Shot" dilution at the time of development (about 1.5 oz of developer for 15 oz total, 6 tubes/sheets) keeps everything fresh and constant and uses so little developer that economic and ecological reasons are a wash. TMX films require very careful consistency in procedure and mix to be reliable; hence, the use of one-shot dilutions rather than mix and replenish.

If you do the test procedures with the step tablet, as recommended by Darkroom Innovations / View Camera, you will spend about 1 hour and $35 to get them finished. You do this once so long as you keep your procedures constant, and you can take pictures instead of wasting time in eternal testing. You get a full chart of varied development for varied contrast range in the exposure, both for Zone System and for the BTZS (useful for incidence reading especially). Take your pick depending on your style. Using the BTZS is part of a larger system. You have to adopt the system (either BTZS exposure or Zone) for the advantages.

Contact Fred Newman at Darkroom Innovations/View Camera Store. He is very knowledgeable and very helpful, one of the few internet camera store owners that knows his large format and is more interested in photography than in selling something. You can email or call. Talking to him is the best way to find out how much he knows.

-- D. Meriwether (david@fpcsat.org), May 18, 2002.

T-max RS seems to work well when one discards Kodak's instructions altogether and instead takes the replenisher packet and adds its contents to the main bottle and mixing. Use it at 1:9 at about 75 Degrees for 7.5-9 minutes for a normal development and you will get some excellent negatives. At this rate you should be fairly economical and consistent. By the way they have a large kit with two 1gal bottles of RS with larger packets for each which cuts the price as well and seems to keep quite well in this form. Rod

-- Rod Klukas (rod.klukas@cox.net), May 20, 2002.

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