Tmax 400 question

[Jim Andrada]

I tried some Tmax 400 a couple of weeks back and developed in Tmax developer in a Jobo. Negs were really dark, although quite clean and usable

But the more I read up on it the more confused I get. Kodak recommends in their Tmax/Tmax RS developer documentation that the same development time be used for ISO 400 and 800 - this seems a bit strange to me and makes me think maybe I should just rate the film at 800.

Also they make a comment that the development time should be reduced 20 to 30% for use in condenser enlargers. So should I interpret this as meaning I should reduce development time for scanning (I'm guessing it does but...)

I do like the recommended 75 degree processing temp as the "cold" water here is over 80 now so higher temp means less need for ice cubes to bring it down - I'd love to see a 100 degree dev temp though as I wouldn't need to chill the water.(one of the reasons I like Ilford XP2 in C-41!)

Anyhow, would appreciate any comments on the film/developer combo

(By the way, I ran the test with 120 film so used regular Tmax developer, not the RS version)

[Gudmundur Ingolfsson]

You need to reduce the times Kodak recommends as developing times for 15% when developing in a JOBO !

[vinny]

I don't reduce the times and my prints don't complain.

[Oren Grad]

But the more I read up on it the more confused I get. Kodak recommends in their Tmax/Tmax RS developer documentation that the same development time be used for ISO 400 and 800 - this seems a bit strange to me and makes me think maybe I should just rate the film at 800.

Here's what Dick Dickerson of Kodak said about it back in 1988 when the film was introduced and that recommendation was first made:

"If you extend development with T-Max film one stop underexposed, you get significant grain. The increased contrast can make the negative difficult to print, with little real speed gain or enhancement of shadow detail. The net result is you'll get more pleasing prints if you don't push development."

"T-Max Tips", Darkroom Photography magazine, July 1988

[Jim Andrada]

Hi Oren

That's exactly what I would expect - hence why would they show the same development time for 400 and 800? That's the part I find strange. I would have expected to have a longer development time for a 1-stop "push".

@Gunmundar: Re the Jobo and reducing time, I was using the times Kodak gives for rotary drum processing so I would think they had already factored the reduction for constant agitation into their recommendations.

[Oren Grad]

That's exactly what I would expect - hence why would they show the same development time for 400 and 800? That's the part I find strange. I would have expected to have a longer development time for a 1-stop "push".

To state his point more directly, Kodak's tests of T-Max showed that according to their criteria for print quality, increasing the development time for one-stop-underexposed film made it look worse, not better - hence the recommendation *not* to extend development.

Ultimately, what looks best to you is up to you - your criteria for print quality may be different from theirs. Try it and see!

[Jim Andrada]

Hi Oren

Yes, I got the point and yes, I will give it a try (maybe tomorrow) but it does strike me as strange that they aren't recommending a one stop push via extended development to go from 400 to 800, they recommend the exact same development time for 400 and 800 - unless their point is that a one stop difference is within the tolerance for a "good" negative - which also doesn't make sense because then everyone could just rate it at 800.

Anyway I'll try a few variations and see how they come out.

[Mark Barendt]

Jim, it may help to think of this in separate pieces.

First is that the real film speed doesn't really increase much with plus/push development, a little, but nowhere near 1:1. Reducing exposure always results in less usable shadow detail on the negative even if you push develop, but that doesn't always matter.

Second is that there is a safety factor built into the ISO standard. Reducing exposure 1 stop, by choice or by accident, for normal mortals will normally have no notable effect on the print. There is a large range exposures that good prints can be made from. With Delta 400 or TMY, with my normal metering techniques, with film developed for normal 400 speed, and my normal subject matter; I have tested and I can get nice prints from these films exposed at EI's anywhere from 50 to 1600, YMMV. (Not claiming exact copies, just nice prints that do what I intended. Also not claiming that shooting wild is the best way to do things, I normally meter carefully but will also happily take a grab shot with out changing my exposure settings.)

Third is that the ISO standard assumes a standard developing regime and metering techniques. Shooting a 400 film at 800 isn't standard. As soon as you move away from box speed you and Kodak start guessing about what will work best, Kodak's suggestions for speeds other than 400 are based on lots of practical testing not the ISO standard, YMMV. If you are using the say the zone system or BTZS to determine your EI, then the ISO standard and Kodak's directions do not apply at all, you are on your own so to speak.

Forth is that adjusting film development changes the printable range, it changes the way all the tones in the print relate to each other. IMO, given the limited gains in speed available, I simply use normal development, this maintains the normal tonal relationships in the print.

[Bruce Barlow]

For years I followed the Picker Doctrine of testing film speed for my equipment.

These days, I just rate it at half the manufacturer's rated speed, and then test for the proper development time. At half speed, I get tasty, rich shadows. Works with Tri-X, T-Max 400, and HP-5. Development time is less, which I gather is a good thing. Works for me.

[peter schrager]

from a fellow apuger...develop 1+2 in xtol semi..that means initial rotation; then at 3 minutes; then at 6 minutes; then at 9 minutes; then at 12 minutes; for a total of 13 minutes...I do it in a tray for sheet or tank for smaller format.....ASA 400....there is no better way
have a nice day
peter