Newbie: E.I. Test for TMax 400

[Michael Heald]

Hello! I've started to shoot 4x5 TMax 400 after shooting TMax 100 developed in TMax RS with a continuous alternating Unicolor roller.
I set up an E.I. test with a backgrund that was evenly illuminated with daylight photofloods, according to my Pentax analog spot meter. I shot four sheets - at ASA400, faster by 1/3 stop, less by 1/3 stop, and less by 2/3 stop. I recently had the lens CLA'ed at SK Grimes so I have exact shutter speeds. I kept the shutter speed the same and changed the f-stops for this E.I. test.
The lower ASA ratings give me between 1/2 and 1 stop of density compared to film base plus fog. I used the spot meter and a light box to check this. The Pentax spot meter is measures in 1/3 stops. From what I've read, Ineed 1/3 sto density difference for zone 1 cmpared to film base plus fog.
The test at ASA 400 showed between 1/3 and 1/2 stop. At ASA 533 shows about less but still between 1/3 stop and 1/2 stop on repeated measurements, usaually closer to 1/3 stop.
I've read that most folks on thsi forum stated that they meter TMax films slower than its rated speed, not faster.
With my TMax 100 films and TMax RS, I thought I was getting some overdevelopment on my negatives. My next step is to test development times with zone 5 and 8 exposures.
If the recommended times by Kodak for drum processing results in some overdevelopment for my setup, would this affect zone 1 like this?
I suppose the best way to sort this out would be to check the development test, then repeat the zone 1 exposure test. I'm curious what folks with more experience in determining personal E.I.s have found. Best regards.

Mike

[steve simmons]

Your Zone 1 density should be approx .1 above film base plus fog.

I suggest the minimum time for max black test that Fred Picker described in his book The Zone VI Workshop. This uses your enlarging setp and printing paper as part of the process and it is generally foolproof.Other places to see a good descrption of this test process are in my book Using the View Camera (check your libary) or in the Jan/Feb 06 issue of View Camera magazine. If you don't have a copy let me know and we will send one to you.

steve simmons
www.viewcamera.com

[Michael Heald]

Hello! Thanks, Steve. I read your article wiht interest when it first came out, and aain as I set up this test. I'm scanning now, so I don't have an enlarger to use, that is why I thought using the spot meter would give the information I need. Best regards.

Mike

[Brian Ellis]

"If the recommended times by Kodak for drum processing results in some overdevelopment for my setup, would this affect zone 1 like this?"

In theory it shouldn't. The reason why you use Zone I for your EI testing, and the reason why you do the EI testing before the development time testing, is that development times are supposed to have little effect on Zone I densities after you've reached about 30% - 50% of the "correct" time. So again in theory, you'd have to be way off in your times (or something else) to get a full stop change in Zone I densities as a result of overdevelopment.

Any rating that gives you between 1/3 and 1/2 stop above fb+f F is probably good enough, 1/3 of a stop being .10 above and 1/2 stop being .15 above. If you're using a diffused light enlarger I think the usual recommendation is .10 to .12 above fb+f. If you start worrying about the difference between .12 and .15 when sometimes you get one, sometimes the other or something in between, I think you can drive yourself crazy. There are enough other variables involved from day to day that an inconcistent difference that doesn't vary by more than a third of a stop is probably not important. I'd use 400 to start with and see what happens. If you get consistently thin shadows then you might rethink your testing but based on all you've said here it looks like that should work.

I learned the basics of zone system testing from Fred Picker's book (though I don't use the minimum time, maximum black method). It's been a long time since I read that book but I vaguely recall that he either suggests not using artificial light for the testing or suggests making some adjustment if you do (or maybe he's talking about light that isn't daylight balanced). I don't have the time to find my copy of the book and check, maybe someone else can. But if my vague recollection is right then you might try testing under daylight and see what happens. This makes things more difficult because, as I learned the hard way, it isn't easy to make sure that the light stays the same in the course of the tests. But it might (emphasis on "might") be more accurate.

FWIW, I stopped doing my own testing about five years ago. The View Camera Store will do the testing for you and produce more and IMHO better information than you can derive on your own for about $30 (unless they've discontinued this service, I haven't checked lately). I thought it was a bargain in terms of time and film saved. The last time I did my own testing using traditional methodology I went through a box and a half of film.