Need help finding correct stock & working dilutions for Kodak T-Max RS

[Bob Coon]

I am new to developing 4X5 film (having sent out for lab development in the past to just get underway using a 4X5) Now I am turning my attention to development at home. And am a bit confused.

Using Kodak T-Max 400 film
Developing in T-Max RS
Develop 5 minutes at 75F

Kodak's literature is all about time and temps and a bit lacking on the mixing of stock and working solutions from the A and B chemistry.

My question: What is the correct mix for Stock and the correct mix of that Stock for a Working solution? I seem to have found 3 different options and need some help putting together the details.

so... do I

Mix A+B together for stock (no water).
For usage, dilute 1:9 with H20 for working solution.
Making about 10 quarts total.
e.g. - Dump the little bottle into the big Kodak bottle - add 100 ml from that Kodak bottle and add water to = 1 liter for usage.

or...

Mix A+B together add H20 to make 1 gallon of stock.
For usage dilute 1:9 with H20 for working solution.
Making 10 gallons total.
e.g. - Dump the little bottle and big bottle together add water to one gallon - then take 100 ml from that gallon add water to = 1 liter for usage.

or...

Mix the A+B together add H20 to make 1 gallon, then divide that into two 1/2 gallon containers.
For usage, use one 1/2 gallon for development returning used developer back to bottle replenishment style.
Add in from 2nd bottle at a rate of 1.5 ounces per (one 8x10 sheet or the equivalent of four 4x5 sheets, or one roll of 135-36) processed. (meaning the 1/2 gallon grows in volume eventually reaching a full gallon right?)
When the second half gallon is used up the developer is exhausted and ready to be replaced.

-?-

Each of these scenarios have very different dilution outcomes. Which is it? Can anyone shed some light (pardon the pun) on the subject?
Thanks in advance.

[PViapiano]

Your first example is the best method.

I used to do it a bit different via a method sent to me by Kirk Gittings, but which still kept the A+B solutions separate, although mixed with water. I mixed Part A with enough distilled H20 to make 32 ounces, then mixed Part B with distilled H20 to make 32 ounces, and labelled the bottles.

When it came time to use them I used the ratio 1:1:6, which works out to 1:8.8, very close to the 1:9 recommendation, and it always worked perfectly for both sheet and roll film.

I'm not sure if longevity would be affected by mixing A+B from the outset, but the way I describe above it lasted for over a year without any noticeable degradation.

[EdWorkman]

I broke all the rules [ and survived just fine thankyou]
I figured part B was separated out cuz it would spoil. I called Kodak to ask what was in B, but the nice phone folks could only address MSDS issues. Since I usually develop film sporadically, I didn't want to mix the stock A+B , use part of it, then have the rest spoil, so I went ahead and [highly] diluted part A [only] for oneshot use on TMY 120- that is, only enough for one tankful at a time- like i learned from Ansel and HC-110- only it's easier with RS account it's a lot runnier than HC-110 syrup. I did IIRC do a set of test rolls at EI 250 and 400 and decided that everything was fine, even at 400, so I never looked back. I haven't tried it thus with sheet film, nor with "TMY-2". So what IS part B anyway?

[PViapiano]

I've heard of some people just tossing the Part B...

[rcjtapio]

I just mix part A & part B together & store that way in the original bottle.

At the time of development I mix 3 oz. out of the bottle with 21 oz. of water to make 24 oz. of working developer (1:7). Some people like 1:9.

N development (for me) is 7.5 minutes in a Jobo drum for T-Max 400, constant agitation, after a 5 minute water pre-soak all at 75 degrees.

Works for me.

[Richard M. Coda]

I mix the Part B in with the Part A.

Generally I use 1:9 @ 75 deg for TMax 100 for 7 minutes.

For TMax 400 I use 1:15 @ 75 deg for 8 minutes.

These are for Jobo in Expert tanks at 75 deg., rotation at 3.5

[ic-racer]

Or just use the non-RS.

[PViapiano]

Non-RS isn't recommended for sheet film, if I recall.

[ic-racer]

Non-RS isn't recommended for sheet film, if I recall.

I forgot the 'smiley' on my post, but the non-RS works fine for some (including me). But it is not recommended by big yellow.

[jim kitchen]

My historical notes for T-Max RS indicate the following times, and blends:


Development times are for 75 Degree F (24 degrees Celsius)

One time use development (T-Max rated at ISO 100)

Note: these could be very good starting times for TMY rated at ISO 400 too, but for the moment, I am not certain since I cannot find my notes regarding TMY.



Agitation is continuous from N+2 through to N-2

N+2 T-Max RS (1 : 4) 11.0 minutes

N+1 T-Max RS (1 : 9) 16.0 minutes

Normal T-Max RS (1 : 9) 11.5 minutes

N-1 T-Max RS (1 : 9) 8.5 minutes

N-2 T-Max RS (1 : 19) 14.0 minutes


Intermittent agitation (Compensating Development):

N-3 * T-Max RS (1 : 19) 15.0 minutes

N-4 * T-Max RS (1 : 19) 12.0 minutes

N-5 * T-Max RS (1 : 19) 9.5 minutes


* agitate for first 30 seconds for for each minute during first three minutes, then 15 seconds every two minutes.

N-2 development requires an an additional exposure of one (1) f-stop.

N-3, N-4, and N-5 require an additional exposure of two (2) f-stops.


I use XTOL with TMY, and I will post my development times in another post, once I finish a few more tests. Unfortunately, I have not used T-MAX RS for quite a long period of time.

jim k