confused about the "active chemicals" for a jobo : LUSENET : Large format photography : One Thread

After doing some tests and reporting earlier in this forum, I found that using TMAX RS 1:9 in a Jobo 2583 left me with streaking problems. When using it at 1:4, I had great results.

Now I've been looking into the expert drums (preferrably the 3010) and ran in to the chart about active chemicals needing to be 50ml per 4 x 5 sheet.

I need to know if I'm understanding this correctly. 10 sheets need 50ml each of active chemical. (10 x 50 = 500ml) With a 1:9 dilution scheme, I will need 5000ml? That's not right!! I normally put 1000ml into my jobo which means only 100ml is active solution. I find it hard to believe that I can only develop 2 sheets when my jobo can hold up to 18 sheets! Hope my common sense hasn't given out....

-- Mark Wiens (, January 15, 2002



take a look at Kodak Document J-86 (can be found on Kodak's Website). It states that you need 45ml replenishment solution per one roll of 136-36, which is usually stated as 80 square inches of film. That means four 4x5"sheets or one 8x10" sheet.


-- Thilo Schmid (, January 15, 2002.


I use the Jobo ALT2500, with the expert drums, 4x5, and 8x10, the drum states 210ml for either one. I have had good results with this. When doing B&W, have had to alter the program to increase the clearing agent by an additional 30 seconds.


-- Bill Jefferson (, January 15, 2002.

The total amount of working developer you need is correct at 500ml, you are confusing active chemical with total amount needed to process the 10 sheets of film. When you make up your 1:9 dilution that is your "active chemicals". In other words, for 10 sheets of film in the Jobo 3010 Expert Drum, mix 50ml of developer with 450ml of water for a dilution of 1:9. I use a 3010 drum for all my 4x5 processing here at Labwork-the black & white lab. We also use other Expert Drums for 5x7 and 8x10 film sizes with excellent results. Regardless of how many sheets I process in the drum however, I always put a liter of chemistry in to ensure even development; if you put too little in you may not get consistent results. This is to be sure the film gets fully submerged in developer as the drum rotates, better to be safe than sorry as this is not reversible after processing.

-- Jeffrey Scott (, January 15, 2002.

Mark: When you dilute your developer that much (1+9), you are right, you won't be able to process very many sheets at once due to max volume considerations of your Tank and motor. Your math is on, but be sure to have your original figure (active volume needed to process one sheet) down before woking the math.

Additionally, if you are using a CPA-2 or CPP-2 model 1,000 ml final volume is going to prematurely burn out your Jobo motor, IMHO. Better to find something in the 400-600ml range - max!, especially if using the already massive expert film drums.

If you're commited to the Jobo, you may want to change to a developer you can live with which does not need such high dilution ratios. That way, you'll be able to process more than just 2 sheets at a time, for instance.

-- Andre Noble (, January 15, 2002.

I'm not sure about which "dilution" you are talking in the context of T-MAX RS. The required replenishment solution is independent of the tank size.


-- Thilo Schmid (, January 15, 2002.

If you want to follow Anchell & Troop's conservative guideline (250 ml of a developer's basic dilution per 80 square inches of film) you will need 50 ml of T-Max RS per *four* sheets of 4x5. This means, at 1:9, you'd have to limit the 3010 drum to eight 4x5 sheets with 1,000 ml of dilute developer - - 100 ml concentrate and 900 ml water. That's maximum motor load for a CPA/CPP-2. On an Autolab, just bump it up to 1,125 ml and put film in all ten tubes. If you think A&T are too conservative, try 10 sheets in the 1,000 ml and see how consistent your results are with varying combinations of exposed images.

-- Sal Santamaura (, January 15, 2002.

TMAX RS has no dilution rate other than using the straight stock solution (mixed as per directions...mix the whole 1 qt. bottle to half a gallon of water, add packet of pt. B, top off with water to make 1 gallon). This is the working developer. Mix up a second gallon the same way. This is your replenisher. You repl. with 45 ml of this to each 8x10 sheet (4-4x5s, 1-135-36 etc.) in the working soln. The working soln. lasts 6 mos. in a tightly closed container/ 1 month in a tank with a floating lid & cover. If you run control strips & figure out your process, you may get by with more or less replenishment....if the times are too short (under 5 min.) in your process, you can modify with 28% acetic acid to lower the pH and slow down the process....

Those are the instructions as per Kodak...know them by heart, because we've been running it this way for almost 7-8 years now in our tank line....there are no Kodak instructions for diluting TMAX RS--that comes from people like John Sexton apparently, which may work okay, but then you have to chuck out just about everything you'll read from Kodak. But the stuff was made to run straight & for using in replenished lines.

-- DK Thompson (, January 15, 2002.

I use a uniroller 352 motor base to agitate my jobo 2583. I use TMX 4 x 5 film. If you go to the info about the film under, you will see developing times for 1:4, 1:7, and 1:9. I guess now I'm really confused about the differences between the active, stock, and total, and on which should I base my 50ml per sheet?

Jeffrey, you claim that jobo's recommendation of 50ml of active chemical is for the whole lot.

Sal, A&T says that 250ml per 80 sq in using the developer's basic dilution. Isn't TMAX RS's basic dilution 1:4?

Andre, I'm glad someone thinks my math is right on, but what is my active volume needed then? I've considered XTOL, but I wish I could stick with a liquid concentrate.

I would like to jump into using the 3010 drum, but that's another $300 investment that I might be able to avoid if I figure out what to do about RS or change to something else.

Thanks for all the replies so far too!

-- Mark Wiens (, January 15, 2002.

DK: Well, you ought to tell Kodak that T-Max RS is only for use in a replenished tank line. Take a look at this Kodak page: 32/f32b.shtml

to see their "official" recommendations for rotary processing using T-Max RS at 1:9.

Mark: Yes, T-Max RS' basic dilution is 1:4. At that dilution, 250 ml of working developer includes 50 ml of concentrate. So, regardless of dilution, per A&T 50 ml of concentrate is required for each 80 square inches of film. Thus the quantities I mentioned above for 1:9.

-- Sal Santamaura (, January 15, 2002.

John Sexton uses T-Max RS at 1:9 in his Jobo 3006. His development is extremely consistent. Maybe the 3010 is pushing it.

-- Chauncey Walden (, January 15, 2002.

Sal, I can't get that page to load up...but if that's the old f-32 pamphlet on TMAX Films and TMAX Developer (J-86), I have those in my hand right now....TMAX Dev. is not the same as TMAX RS. Here's the link to Kodak's Professional listing of TMAX Developers: html

That's pub. J-86.

Am I missing something here if I read this:

"T-MAX Developer is available as a one-part concentrate in sizes to make one gallon and five gallons of working solution. You can easily mix smaller volumes by mixing one part of the concentrate with four parts water. T-MAX RS Developer and Replenisher is available in convenient sizes to make one gallon and ten gallons of solution; use this solution as a working-tank solution or a replenisher. The ten-gallon size consists of two separate units, each to make five gallons of solution."

Every little sheet that comes packed into a box of RS says absolutely nothing--never has--about diluting it. I just pulled one and this is what it says: "unlike T-Max developer, Kodak T-Max RS Developer and Replenisher is not intended for mixing smaller volumes. Mix the _entire_ contents of part A and Part B to prepare a complete developer and replenishing solution."

The basic dilution for TMAX is 1:4, TMAX RS is a different developer....I can't speak for Kodak, so ask them what the "official" repsonse is if all the tech sheets say something else.

-- DK Thompson (, January 15, 2002.

Sal...ah-ha! Now I see it...leave it to Kodak to bury the crap on their website....the F-32 I have here is from the 90' looks like the one you found is an addendum labeled Pt.2 from 9-2000....I see the dilution specs for the RS, but it's confusing as hell when you read all the fine print, and seems contradictory if you read the tech sheets for the developer. My apologies....

-- DK Thompson (, January 15, 2002.

I use a Expert 3010 and a 2500 series drum on a Uniroller base and thanks to santa am now using both on a CPA-2. I have followed John Sexton's suggestions that are included in his workshop handouts. i use T-Max RS. I mix Part B into Part A and that becomes my stock. I do not mix the developer into a gallon quantity! Then I dilute that 1:9. For 12 sheets in the 2500 drum or for 10 sheets in the Expert drum, i use 900ML. That is 90 ML TMax RS and 810 ML water. i process Tmax 100, EI 80, for 10 minutes at 75 degrees. I used Sexton as a guide and then made tests on my own. That works well. Bob

-- Bob Moulton (, January 15, 2002.

DK: No apology necessary. I used that html "part 2" link only because I couldn't find the .pdf link on Kodak's site at the moment. Very strange search results sometimes at

The oldest F-32 paper copy I can locate here at the moment is dated October 1999, and it has the same info as the html file; I remember high dilution T-Max RS rotary recommendations being included for quite a few years before that. I suspect it's all traceable back to Sexton anyway, in his consulting capacity for Kodak.

-- Sal Santamaura (, January 15, 2002.

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