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  1. #31

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    Quote Originally Posted by Photo Engineer View Post
    Many answers to many questions. Yes, digital is partly to blame for the sheen, which does not bother me!

    PE
    Ha! It bothers some of us when we use glass carriers and get Newton rings on the emulsion side! - which I still haven't figured out how to get around! It's a fairly well known issue with TMax and a few well known names gave up on TMax for this reason.

  2. #32
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    Michael, there are many solutions to your problem. One, suggested by EK years ago was to use Opal glass which is frosted and prevents Newton rings. Also, there are methods to prevent them.

    Even in the most critical applications, we did not find glass carriers significant. In fact, oil immersion carriers with glass were of more use. We had some contact with that as far back as 1962 when I was at Cape Canaveral.

    Also, with a mixed workflow which includes scanning (the most significant change yet) this helps imaging. So, there were solutions and tradeoffs. It seems to work for most.

    PE

  3. #33

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    Quote Originally Posted by Tom1956 View Post
    Reading this almost causes me to regard rocket scientists as [...] in comparison to the film technology. Cupertino seems a building full of monkeys. I had no idea. This is chemistry folks, in it's full glory. Mind boggling.
    Yes, by comparison, rocket science is comparatively easy. It's mostly plug-and-chug mathematics, but very little in the way of creativity unless someone's trying to do something significantly different.

    Photochemistry...every chemical added adds a possibility of unintended interactions... think of the growth rate of the permutation function P(x,y) and the combination function C(x,y) as x and grow. So to minimize a side-effect.. you can add another chemical.. oops, now you've just increased x yet again.. or figure out some other way to shunt the effects of the side effect to a negligible amount.
    Last edited by David A. Goldfarb; 06-30-2013 at 05:33 AM. Click to view previous post history. Reason: Offensive language deleted in quote.

  4. #34
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    Well, in rocket science, you cannot easily do factorial experiments. In photo engineering it is quite common.

    PE

  5. #35

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    I have a good friend who was a "rocket Scientist", back in the '50s and '60s. Back then at least, it was anything but "plug and play" In every field, From Rocket Science to short order cook, it looks easier than it is.
    Bill

  6. #36

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    Well, frosted glass below the negative is not a good idea. As for wet mounting/oil emersion, this is a last resort at best, not something anyone would want to have as part of a normal workflow. I've tried a number of coated/thin film optical glasses in an effort to get rid of Newton rings when they occur on the emulsion side of TMax. Since it is an intermittent problem, it is difficult to say with certainty but I'm pretty sure none of them worked. The "best" solution I've found is to use a sheet of unexposed, fixed Tri-X 320, which has just enough "tooth" on both sides. But in the end, better off using Ilford. It's a shame since TMax 100 and 400 (TMY-2) are unique films. I had naively assumed there was something about the film that meant the emulsion overcoat had to be glossy. Now that I know it was simply a compromise in ease of analog workflow for the sake of scanning quality, I don't feel quite as bad about dumping them.

  7. #37
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    Well, Michael, I have made enlargements of up to 16x20 from both 120 and 4x5 negatives without a glass carrier and they are quite sharp. Some of them are on display here at our mall at the instruction center. I can understand that some people have preferences, but I seem t be able to get along without glass. We did at EK as well in most cases. They used liquid filled glass carriers for 30x40, but that was more for scratch elimination.

    However, this is far from the intended topic in some ways.

    PE

  8. #38

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    Point taken - apologies for the digression - but I'm happy to have learnt a few more things about making film anyway

  9. #39

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    Back to the original topic : I'm very glad this thread got revived; and we were given a succinct explanation of why color negs have traditionally
    come out with so much pumpkin and poison green - and perhaps why they have improved so much in recent years. Right now I'm making prints
    from color negs which almost anyone would think came from chromes, except that the white borders would be a giveaway. And yes, 30x40's
    with registered masks would be unthinkable without glass antinewton carriers.

  10. #40
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    Drew, that "bad" example with cyan, grape and pumpkin was only intended as an example. NO Kodak film, or any film I know of, was produced without interlayers and scavengers. Even the earliest Agfa color negative film had interlayers and scavengers.

    I don't know what films you used in the past but they all had pretty good correction as well as good grain and sharpness. Recent films such as Ektar and Portr are far far better.

    PE

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