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  1. #51

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    Bill, as you know, I'm a stickler for test design. Given the difficulties involved, in addition to repeat testing (obvious) it is often helpful to do things a few different ways, which is what I always do. It takes time, of course. I remind everyone the point of this exercise was to compare shapes and the major characteristics of the curves. It is obvious repeatability to within 1 density point is not possible, nor is it necessary. Unfortunately the context of Mark's original post has been lost. In addition, nobody said fine prints cannot be made from this type of curve, nor is anybody knocking TMY-2, a wonderful film. As for the "curves shmurves" business, there is nothing about the posted curve shape that would indicate the film cannot hold 12 stops of good separations, although it should be pointed out a variety of films can do that.

    Quote Originally Posted by Bill Burk View Post
    I wouldn't go so far as that. I called up a radio station a while back because my oscilloscope was showing a 45-degree line where the stereo scatter fuzzy oval should be. They thought I was a lunatic until I double checked by listening in my car. No it wasn't my equipment. And my scope is nowhere near calibrated. All their lab equipment was switched on the digital signal so they didn't notice the board on the analog side was switched to mono.

    Meanwhile to add a possibly useful question to the thread. Is this the kind of step wedge layout used for testing?

    http://www.apug.org/forums/viewpost.php?p=1480607

    If so, can you test with an offset, or 90-degree angles to your usual. Maybe you are seeing an effect where the outside edge of the film receives greater development than the center.

    p.s. I work for Kodak, but not in film - here I am a hobbyist. The opinions and positions I take are my own and not necessarily those of EKC.
    Last edited by Michael R 1974; 03-29-2013 at 06:44 PM. Click to view previous post history.

  2. #52

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    Just bringing this thread back in case Mark was still looking into the TMY-2 curves. I ran some more samples from that batch, samples from batch 0166 and samples from the newest batch I could find (0169 - I'm assuming this is the newest batch as it seems to have the furthest expiry date).

    I seem to be getting essentially the same curve shapes in all three batches.

    Michael
    Attached Thumbnails Attached Thumbnails TMY-2.jpg  

  3. #53
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    To me it looks like a blending problem.

    PE

  4. #54
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    I scanned back through this thread because I thought someone mentioned what you might expect from such a curve in a real world printing situation but I couldn't find it. Could someone lay that out here, for my sake? I understand the basics of toe, shoulder, straight line areas but this shape is a bit confusing to me. Thanks in advance.

  5. #55

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    PE: What if this is simply how it is supposed to be (within spec)? Suppose it is actually a problem, how likely is it this could persist through several batches without being corrected?

    On a personal note this curve wouldn't bother me as a user. From a printing perspective it is essentially a straight line with some extra contrast in the very high highlight densities. Actually - this is not all that different from Acros.

    I guess it just confuses me a little because when TMY-2 was first introduced I remember seeing a few plots comparing it with TMX (I think Sandy King did an article) and the curves seemed quite similar except a slightly longer straight line for TMY-2 (more gradual shoulder for TMX). The curves above, however, are quite different than TMX.

  6. #56
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    Quote Originally Posted by Michael R 1974 View Post
    On a personal note this curve wouldn't bother me as a user. From a printing perspective it is essentially a straight line with some extra contrast in the very high highlight densities. Actually - this is not all that different from Acros.
    Thanks, Michael.

  7. #57

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    Quote Originally Posted by Shawn Dougherty View Post
    I scanned back through this thread because I thought someone mentioned what you might expect from such a curve in a real world printing situation but I couldn't find it. Could someone lay that out here, for my sake? I understand the basics of toe, shoulder, straight line areas but this shape is a bit confusing to me. Thanks in advance.
    Shawn, here's a cleaner version showing only one curve of approximately 'normal' contrast from the series above.

    To make it more relatable I changed the labeling on the X-axis and added "Zone" indicators.

    What you have is a very straight curve (constant contrast) up to around Zone VIII. After that contrast increases and remains relatively straight until around Zone XII with a gradual shouldering (reduction in contrast) thereafter.

    In the real world this means you have a pretty straight line until you get into the high highlights where you have a lot of local contrast. If you have those densities in the negative, it would take some extra burning in to bring them into the print. Not really a big deal. The extra contrast in the extreme highlights would tend to offset the compression in the toe of the paper. Basically all I'm saying is you'd have to do more burning in, but it would be slightly easier to retain local contrast (detail) in the highlights if you're burning them down at lower grades.

    Fuji Acros has a similar curve, with a less gradual shoulder.

    This type of curve could be a better candidate for compensating and other extreme contraction procedures because since the film inherently has high highlight contrast, it can stand more contraction without completely flattening the highlights.

    Note different people might like or dislike a given curve shape so to some extent this is all subjective.

    It is also important to note if you're regularly using TMY-2 you've probably subconciously adapted your printing to the curve anyway, so nothing to worry about - unless it is not the normal curve for the film.
    Attached Thumbnails Attached Thumbnails TMY-2_XTOL.jpg  

  8. #58
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    Ok, what I have seen here are good and bad curves. Now, what is it due to? If you have good and bad from one batch then it is processing but if you see good from one batch all the time and bad from others all the time, then it is probably a bad blend. Now bad? Well, what do the photos look like? If they are ok, then there is no problem.

    You see, there is a curve tolerance spec, and if the film is within that (D76) then it is released. If not, it is destroyed as scrap. I cannot tell, without extensive tests, if these batches are good or bad, but the curves look like a bad blend due to the kink in the center. And this is the perennial problem encountered when you use blends of emulsions. If you miss, you have a kinked curve and if the kink is too bad, then the batch is bad.

    I would not worry if the photos taken look good.

    PE

  9. #59

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    Interesting. Thanks for the additional insight as always.

  10. #60
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    Quote Originally Posted by Michael R 1974 View Post
    Shawn, here's a cleaner version showing only one curve of approximately 'normal' contrast from the series above.

    To make it more relatable I changed the labeling on the X-axis and added "Zone" indicators.

    What you have is a very straight curve (constant contrast) up to around Zone VIII. After that contrast increases and remains relatively straight until around Zone XII with a gradual shouldering (reduction in contrast) thereafter.

    In the real world this means you have a pretty straight line until you get into the high highlights where you have a lot of local contrast. If you have those densities in the negative, it would take some extra burning in to bring them into the print. Not really a big deal. The extra contrast in the extreme highlights would tend to offset the compression in the toe of the paper. Basically all I'm saying is you'd have to do more burning in, but it would be slightly easier to retain local contrast (detail) in the highlights if you're burning them down at lower grades.

    Fuji Acros has a similar curve, with a less gradual shoulder.

    This type of curve could be a better candidate for compensating and other extreme contraction procedures because since the film inherently has high highlight contrast, it can stand more contraction without completely flattening the highlights.

    Note different people might like or dislike a given curve shape so to some extent this is all subjective.

    It is also important to note if you're regularly using TMY-2 you've probably subconciously adapted your printing to the curve anyway, so nothing to worry about - unless it is not the normal curve for the film.
    Excellent. Thank you for laying that out there, Michael. I really appreciate it. This makes total sense. I will often times make a couple of test sheets with my highlights burned in at different grades and pick what I like the best, so I would definitely be compensating for any required change due to increased contrast in the highlights.



 

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