T-Max 400 has boomerang curve

Discussion in 'B&W: Film, Paper, Chemistry' started by albada, Mar 16, 2013.

  1. albada

    albada Subscriber

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    As part of testing a new developer I've created (in "Progress on XTOL-concentrate" thread), I've been testing and plotting all films made by the big three makers. T-Max 400 has this interesting curve:

    20130316-TMY2-Boomerang.jpg

    It's shaped like a boomerang, and that will cause highlights to block up sooner. If you're spending much time burning-in your highlights with T-Max 400, this might be why. For comparison, here are curves for HP5+:

    130312-HP5-214D-XTOL-CloseSpeed.jpg

    Once past the toe, HP5+ marches in a straight line like a soldier. This also shows that my own test equipment and methods aren't producing that boomerang curve. I saw this issue with T-Max 400 a few months ago, but I blamed my own testing. But results with other films show that my tests are okay. Interestingly, Tri-X also makes a boomerang:

    130306-TriX-214D2-XTOL.jpg

    But the boomerang for Tri-X is facing up instead of down, and the change in angle is small. It'll give you a bit of compression (compensation) in the highlights.

    T-Max 400 worries me. In a prior posting, PE said this means that Kodak is having trouble blending emulsions correctly. I think T-Max 400 has two emulsions. Hold a piece of paper against the monitor to use as a straightedge, and you'll see that the curve consists of two straight lines. I suspect their slopes are supposed to be the same.

    Mark Overton
     

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  2. jp498

    jp498 Member

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    My highlights are awesome with tmax 400; never have to burn them in. I use pyrocat HD or PMK and develop in patterson tanks or combiplan tanks. What you haven't mentioned is your agitation scheme? Rotary processing? Tank? Developer and dilution? Lots of things can change results to be different than what you've posted. It's a versatile film, and "responsive to changes in development".
     
  3. Rudeofus

    Rudeofus Subscriber

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    Is there a chance that these TMAX 400 curves straighten out somewhat if you dilute your developer?
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    I'm surprised by those curves. They look nothing like the data I have seen. Something is wrong with the film or the process (agitation?) or whatever.

    I would check it out with other options and then contact EK if this persists.

    PE
     
  5. Michael R 1974

    Michael R 1974 Subscriber

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    I'll run some TMY-2 tomorrow and see what curves I get.
     
  6. albada

    albada Subscriber

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    Further info about my process:

    I agitate using Fuji's method: Once per minute.
    I'm using a stainless steel single-reel tank with 200-210 ml of developer (barely covers the film).
    XTOL was used stock (not diluted).
    The T-Max 400 is batch number 0167 bought a few weeks ago and kept frozen, and the XTOL was mixed last week. So everything is fresh.

    Regarding more dilution: The concentrates shown in those curves are similar to XTOL diluted 1+1, so I doubt dilution makes a difference.

    Regarding agitation: The concentrates take about twice as long to develop, so they'll get twice as many agitations as XTOL. Since they develop at half the rate of XTOL, the behavior of the concentrates should be similar to agitating XTOL twice per minute. Yet the curves are identical. I'm curious to see what curves Michael R gets...

    Mark Overton
     
  7. Photo Engineer

    Photo Engineer Subscriber

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    I would contact EK. This looks like too little fast component or a keeping problem.

    PE
     
  8. albada

    albada Subscriber

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    A few more notes:

    In both graphs for T-Max 400, I waited 23 hours between exposure and development. Films have different latent image keeping (LIK) characteristics, and the delay was to simulate real-life usage. I suppose it's conceivable that the two or more emulsions in T-Max 400 could have different LIK decay-rates, so the curve could change based on exposure-to-development delay.

    This boomerang is a form of upsweep. In the thread on "Kodak Tri-X- D76 vs HC110 Dilution B (upswept curve look?)", Bill Burk says he believes that upsweep helps portraiture by improving tone-separation in faces. I didn't think of that. I was thinking more of what upsweep would do to sky and clouds.

    jp498 said "My highlights are awesome". There are a number of possibilities, one of which is that I goofed. Or you might be using a different batch of TMY2. Or maybe TMY2 with pyrocat or PMK produces a straighter curve. Do you have a Stouffer step-wedge? It would be interesting to get the curve.

    Anyway, I exposed a new roll last night, and I'll let it age (LIK) and decide what to do with it once Michael R's results are in.
    Michael: If you post or PM your densities to me, I can plot them using my gnuplot script.

    Mark Overton
     
  9. noacronym

    noacronym Member

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    I never liked Kodak dropping the Plus-X, Verichrome Pan, and Tri-X for this T-max stuff. Never liked it. If it's not broke, don't fix it.
     
  10. AndreasT

    AndreasT Member

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    My curves using X-tol 1+1 are similar. I just have a hump which goes up in the lower half. I would say I also have two curves in one but the upswept part is relatively high up so if one doesn't over expose too much it should still be fine.
    Checking my other developers they nearly all have this hump. Different but somewhere to be found.
     
  11. john_s

    john_s Member

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    I think I remember reading that the upswept curve was favored by studio photographers. But they have control of lighting that we landscape photographers don't have.
     
  12. Michael R 1974

    Michael R 1974 Subscriber

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    Working on it tonight. I just mixed up a fresh batch of XTOL so this test is timely. I will use 35mm TMY-2 as I believe you were doing your tests with that format.

    I would not compare curves to those obtained with Catechol, Pyro, and other low sulfite developers that work on the basis of controlled exhaustion. D-76 would be a better comparison.
     
  13. Michael R 1974

    Michael R 1974 Subscriber

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    Well, my first test won't be of any use. I hadn't used TMY2 with XTOL before, and hadn't used XTOL at stock strength before so I went with Kodak's recommended time of 6:30 @ 68F (which seemed very short) and Kodak's agitation recommendation. Way underdeveloped. I got the equivalent of N-3. I suppose I should have expected this since my TMX times with XTOL 1+1 are significantly longer than Kodak's.

    The shape of the curve did resemble Mark's upsweep, but with this degree of underdevelopment I can't come to meaningful conclusions regarding TMY2's normal curve shape in XTOL so I will have to redo this at least one more time.

    By the way my rolls are from the same batch as Mark posted.

    Apologies.
     
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  15. albada

    albada Subscriber

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    Michael, I suspect something went wrong. I develop TMY2 the same way you did: XTOL (stock) at 6:30 @ 68F, but agitating less than you, and I get normal density and a normal CI of 0.57. What's the density of your leader? Mine is 2.76, which is higher than most films.

    YIKES! I just remembered another detail: I always pre-soak the film! I discovered a year ago that TMY2 gives higher densities when pre-soaked. I give it 4 minutes agitating twice per minute. Sorry, I should have mentioned this earlier. But even so, the lack of a pre-soak should not cause an N-3 pull.

    Anyway, your test is probably useful because I've noticed that under/overdevelopment does not change the shapes of curves much. Could you post your numbers or graph? BTW, thanks for doing these tests!

    Mark
     
  16. Michael R 1974

    Michael R 1974 Subscriber

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    That is disturbing to say the least. I have always needed significantly longer times than Kodak recommends for XTOL/TMax films, and my times have always been consistent. I have no explanation for this. Perhaps someone else should run the tests.
     
  17. albada

    albada Subscriber

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    In addition to a pre-soak, here are a couple more ideas:

    * Inaccurate thermometer (are all times longer than expected?).
    * Something in tap-water damages XTOL. (BTW, I use distilled water because my tap-water is hard).

    If you don't mind running another test, you could do so using your times and process that are known to work. But AndreasT and you have already reported upswept curves, so maybe we already know what the result of another test would be...

    Mark
     
  18. DREW WILEY

    DREW WILEY Member

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    Tmax gets the straightest curve with TMRS developer. But TMX can shoulder off if overexposed in full range lighting; and that's a reason it should not be rated below box speed with certain common developers. Some developers will create an upswept curve at the top with TMY, but you've really got to
    be up there where you don't belong to begin with. I've used a variety of developers with these films, but never XTol - and if Xtol does in fact predictably produce a toe like that, I wouldn't even want to
    bother with it.
     
  19. Michael R 1974

    Michael R 1974 Subscriber

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    Thermometer is certified/calibrated, and I use distilled water for all chems. XTOL/TMax films is the only combo for which my times are long (regardless of dilution - stock, 1+1, 1+3). Curiously with Delta 100 my times are pretty close to Kodak's, and that's with less agitation than Kodak. Very strange. I will redo but I'm sure I'll get the same results as my process is tightly controlled. Perhaps I exposed incorrectly.
     
  20. albada

    albada Subscriber

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    Do the edge-markings look thin? If so, your exposure is probably fine. Anyway, it would be interesting to re-try the process with an added pre-soak and/or longer time.

    Drew, you bring up some interesting points. (1) Like you, I've seen TMX shoulder-off and also recommend that it not be overexposed. But my latest concentrate makes it shoulder-off too soon, so I'm wondering whether to do anything about that. (2) My TMY2 curves in the OP shows the upsweep starting in the upper midtones or low highlights, so it'll affect folks (assuming it's not due to my own goof). Maybe it started farther out in prior batches. (3) The toe of TMY2 looks sharper than most to me; what about it do you dislike?

    Mark Overton
     
  21. StoneNYC

    StoneNYC Inactive

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    So, how do you guys measure this stuff? Like can you explain the process if messing a curve? Do you scan it with a special program or how do you plot it?

    Thanks.


    ~Stone

    Mamiya: 7 II, RZ67 Pro II / Canon: 1V, AE-1, 5DmkII / Kodak: No 1 Pocket Autographic, No 1A Pocket Autographic | Sent w/ iPhone using Tapatalk
     
  22. brucemuir

    brucemuir Member

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    Stone,
    Google densitometer.
    Its a machine that measures silver densities directly off the film.
     
  23. Photo Engineer

    Photo Engineer Subscriber

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    Guys;

    We had this problem at EK. We had standards committees for all work so that all things were as equal as possible!

    PE
     
  24. DREW WILEY

    DREW WILEY Member

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    I use the same standard ole Kodak plotting paper that I've used for decades. No fancy programs. Just
    a densitometer and a sharp pencil. It's translucent, so one can directly compare curves over a lightbox.
     
  25. Michael R 1974

    Michael R 1974 Subscriber

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    Mark, what I'd like to do is run some TMY-2 in both XTOL and D-76. Perhaps my "batch" of XTOL packets is bad. I don't know why that would be but who knows. But I won't have time for this until the weekend so if you want to go ahead, don't wait for my tests.

    While it has been a while since I used TMY-2, in sheets I always got pretty long, straight curves with short toes and a gradual shouldering (slightly more gradual than say Delta 100). Actually I found the curves very similar to TMX, which made TMY-2 an almost ideal large format film for my work (except for the slightly glossy emulsion which can be a serious pain in the ass as far as Newton rings go). So this thread is somewhat troubling.

    PE - how likely is it there is really something wrong with the film? Realistically, can this happen? I mean obviously it can happen, but ?
     
  26. AndreasT

    AndreasT Member

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    I just double checked some of my results. All from the same batch. Basically all TMY curves in my results do tend to be upswept.
    Except with FX-39.