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Thread: Film speed test.

  1. #31

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    Re: Film speed test.

    If you have made up your mind about the film speed to use...

    You can shoot now and test later...

    After all, N-development times such as N+1 aren't defined in terms of minutes until desired target paper range is declared and development tests are done...

    And by circular definition, you can develop the film for any number of minutes - until you actually develop it.

    After that, there is no more need for testing, at least for that negative.

  2. #32

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    Re: Film speed test.

    Thanks to all who provided a specific answer to my specific question. Also thanks to those who provided all the general comments-I was looking for those too. I have found the forum to be a great resource-better than most books because you get multiple ideas on topic-not just that of the book author. I have printed many of the topics in the home page and placed them in a ring binder for reference when performing a specific task. It is hard to find detailed specific instruction on loading filmholders elsewhere. The question-answer forum has answered many questions by just perusing on a regular basis. For example drying sheets of film was one question and one day there was the question and many answers. Thanls for all your help in my photography. I am grateful. ken

  3. #33
    Kevin Kolosky
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    Re: Film speed test.

    People spend a lot of time testing and then things change or you'll have different field conditions or one shutter will be faster or slower than another, etc., etc. Also, in my opinion, people test things bass ackwards. There is so much concern about the negative, and not so much concern about the end product, the PRINT.

    I think the one test that is better than any other test is to find the minimum time to print black on your paper using your enlarger and your lens and your negative that has been developed in your chemistry by you.

    YOu don't need a densitometer, or a bunch of special stuff. All you need is a blank unexposed negative that has been developed for the standard time, and your paper and your enlarger and your chemistry.

    Put the enlarger at the height for an 8 x 10 print, stop the lens down 3 stops, and make a series of short exposures, of say 1 second each. Develop that paper and find the time for the stripe that is as black as the next stripe down. Write that time down. (also, mark the height of the enlarger or you will run into problems with the inverse square law)

    Now, put any other negative that you make in the enlarger at the same height and the same lens setting, using the same chemistry at the same temperaure. Print it for the same time as that black stripe. Develop the print the same way.

    Then look at your print. You will see whether you have enough or not enough exposure(i.e. your ISO is correct) by the dark tones, and whether you developed long enough or not long enough by the high tones.

    Once you do that for awhile you will really start to understand what its all about, and then you can start refining things with densitiometers and pushing and pulling, and all of that stuff.

  4. #34

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    Re: Film speed test.

    Quote Originally Posted by Kevin J. Kolosky View Post
    People spend a lot of time testing and then things change or you'll have different field conditions or one shutter will be faster or slower than another, etc., etc. Also, in my opinion, people test things bass ackwards. There is so much concern about the negative, and not so much concern about the end product, the PRINT.
    .
    Kevin, your point is well taken, the print is certainly of equal importance as the negative.

    However, a few comments in this thread call to mind the old expression "garbage in - garbage out". While testing can certainly be overdone, and, agreed that a beginner should not be over burdened with "zone test stress", it cannot be overstated that the negative has to range within certain reasonable parameters to get a decent print. This is true particularly if speaking in terms of a "fine" display print.

    The beginner's experience should be both enjoyable and disciplined enough to work toward achieving a good quality negative and ultimately a fine print, aided by appropriate negative and print tests which help achieve that goal.
    I know just enough to be dangerous !

  5. #35
    Kevin Kolosky
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    Re: Film speed test.

    "it cannot be overstated that the negative has to range within certain reasonable parameters to get a decent print. This is true particularly if speaking in terms of a "fine" display print."

    I could not agree more. That is why I said that the test will show whether he exposed enough or too little, or developed enough or too little. I should have added "or too much". After all, those "reasonable parameters" are proper exposure and proper development. If I recall there are only 4 mistakes you can make. Under or over exposure and under or over development, and that should be for HIS paper. So the best way to figure that out is to start out by testing HIS paper, and then of course later on getting into all of the refinements that you are talking about which are required to make a fine print - push, pull, dodge, burn, flash, bleach, split develop, and all of the rest of it.

  6. #36
    8x10, 4x5, et al
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    Re: Film speed test.

    What the local experts conveniently ignore is the fact that all this testing has already been done by the manufacturers, using
    calibrated test equipment that's far more accurate than anything we have, operated by technicians who are trained and
    proficient in its use, under controlled conditions, with the goal of optimizing the results obtained by users in the field.

    Personal testing is important, but what it tells you if your results are not as anticipated, is that there's a problem at your end,
    either with incorrect exposure or incorrect processing. The problem needs to be analyzed and corrected.

    But you have not identified a problem with commercial products.

    Of course the commercial recommendations are based on "average" scenes, but a large amount of research has gone into
    determining what "average" is, and you're unlikely to deviate from that in the general case. If your work really is not "average"
    then deviation from the recommendations can be expected. This is pretty unlikely.

    Unfortunately this level of standardization does not exist for home-made concoctions.

    - Leigh

  7. #37
    C. D. Keth's Avatar
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    Re: Film speed test.

    Quote Originally Posted by Leigh View Post
    Absolutely true. Photography is a very complex art/science, with myriad variables. Each individual is different.

    The most obvious and arguably most significant difference is in agitation methods, but there are numerous other processing differences.

    - Leigh
    It's only as complicated as you want to make it. Plenty of fine photographers have gone their entire career shooting tri-X at box speed, developing in D76 to the instructions on the bottle.

  8. #38
    8x10, 4x5, et al
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    Re: Film speed test.

    Quote Originally Posted by Christopher D. Keth View Post
    It's only as complicated as you want to make it. Plenty of fine photographers have gone their entire career shooting tri-X at box speed, developing in D76 to the instructions on the bottle.
    I believe that's what I suggested in post #36 immediately above.

    - Leigh

  9. #39

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    Re: Film speed test.

    It might just be me, but I've had to look at a LOT of negatives and do a LOT of printing before I was able to even notice or appreciate the subtle changes or adjustments one might make as a result of testing.

    It's only after developing and printing (with the same film, same developer, paper and paper developer) upwards of 1,000 sheets that I've even been able to even begin to understand the subtle changes that take place as different variables are adjusted.

    Are you confident you can already tell the difference, with a fairly high degree of confidence, between an over/under exposed and over/under developed negative? I can about 1 out of 3 times. On a good day and if I have good notes.

    I may just be a slow learner - I'm not usually - but after all that, I'm only just beginning to intuitively understand the meaning of "control over one's materials" and be able to anticipate the results of small, deliberate changes.

    I don't want to turn anyone off testing in general, but I think you need to have a good deal of base experience to be able to really understand what you're even doing - or more, what you just did - when you "test" any materials.

    I say go out and shoot for awhile so you can truly understand what "normal" looks like, before you start making these tiny
    little tweaks.

    If testing and reading is the way you want to learn and understand your materials, than more power to ya. I, for one, am doing this (photography) in the first place because I like to make photographs. Testing is for becoming a better photographer, not learning how to be one in the first place.

    We're all different and we all learn differently and at different paces. Some people pick this stuff up right away and have eyeballs calibrated for D-log from birth. That sure ain't me! Maybe you're one of the lucky ones.

  10. #40
    8x10, 4x5, et al
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    Re: Film speed test.

    Well said, Cletus.

    - Leigh

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