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  1. #1

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    Negative reading

    Sorry for spamming the forum.

    I am searching for some examples of how negatives look, in cases of overexposure, underexposure, underdevelopment... and so on.

    I searched, found some things, but nothing satisfactory. Pretty hard to find it as digital image and be accurate (logical why) but if you have any quick resources on this I would appreciate.

  2. #2
    Greg Davis's Avatar
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    There is a good book by Henry Horenstein called "Black and White Photography, a Basic Manual" that gives examples. It will answer many of the questions you have here.
    www.gregorytdavis.com

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  3. #3
    dpurdy's Avatar
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    There is an instrument made for measuring the density of negatives. It is called a densitometer. Otherwise negatives are generally judged from experience.
    I actually have a known density patch taped to my light table for quick comparison of proper high density.
    I do believe a negative should be beautiful to look at.
    Dennis

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    You might look for Ansel Adams' The Negative, which is probably in your local library, and also available at amazon, hard cover and paper back, ands used book stores, (which is where I found mine).
    "We often think that when we have completed our study of one we know all about two, because 'two' is 'one and one'. We forget that we have still to make a study of 'and'."
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    If one is considering exposure and development then there are nine possible combinations ranging from underexposed and underdeveloped to overexposed and overdeveloped. Some books on photography will picture a matrix of these nine combinations and can be very useeful in training the eye.

    The size of a negative really determines how easy it is to read it. LF is the easiest and there are a couple of useful tricks. First, place the negative on a newspaper. If the print can be easily read then the density is correct. The second test for contrast is a bit more involved. One must first determine the contrast looking through the negative at a piece of white paper. Next the negative is placed on the paper and evaluated again. If the contrast appears OK in the first case and too much in the second then the negative is correctly developed. Conversely if the contrast is too low in the first case but appears to be correct in the second then the negative is underdeveloped. The reason that this test works is that light must pass through the negative twice in the second case and this enhances its appparent contrast.
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  6. #6

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    A quick Google search turned up the following. Maybe it will help:

    http://www.olympusmicro.com/primer/p...ingerrors.html

    Best,

    Doremus Scudder

    www.DoremusScudder.com

  7. #7

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    Guys, I have read Ansel Adams books and know what a densitometer is . I need only pictures like in the ones mentioned by Doremus. I don't need lg's, fb-f's or accurate measurements.

    Gerald: thanks for the newspaper tip, great to know it. I need exactly pictures with the matrix you are talking about .

    I also found on google some, but I need more examples, I'm hoping you have some good sources.

  8. #8
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    After looking at negatives for almost 30 years I'd summarize the following:

    Under exposure: usually easy to tell
    Over exposure: very, very difficult tell if a negative is unprintable because looking for good separation in the very dark portions of the negative is almost impossible as the human eye can be 'blinded' by the lighter areas.
    Over Development: usually easy to tell. The negative looks very vivid with a density range identical to the original scene, almost like a slide or transparency. Realize that a properly developed negative will have LESS overall contrast than the original scene by about six to seven tenths.
    Under development: can sometimes be very hard to tell from under exposure.


    The best way to analyze pictoral negatives is to try and print them. Using a denstometer on a pictoral image is difficult even with 8x10. On one of my typical 8x10 negatives there are very few areas that are uniform and more than 3mm in diameter to make a reasonable reading with the densitometer probe. If you are doing ULF, then the arm of the densitometer won't reach to the center of the negative. Using the denstiometer for rollfilm negatives is usually only reliable when filling about 5mm of the frame with a known uniform area of illumination.
    Last edited by ic-racer; 05-05-2011 at 12:32 PM. Click to view previous post history.

  9. #9
    jp498's Avatar
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    Quote Originally Posted by ic-racer View Post
    After looking at negatives for almost 30 years I'd summarize the following:

    Under exposure: usually easy to tell
    Over exposure: very, very difficult tell if a negative is unprintable because looking for good separation in the very dark portions of the negative is almost impossible as the human eye can be 'blinded' by the lighter areas.
    Over Development: usually easy to tell. The negative looks very vivid with a density range identical to the original scene, almost like a slide or transparency. Realize that a properly developed negative will have LESS overall contrast than the original scene by about six to seven tenths.
    Under development: can sometimes be very hard to tell from under exposure.
    This is basically what I observe as well.

    Underexposure/Underdevelopment is observed as thin/weak looking highlights which turn into a lack of shadow detail in the print.

    Underdevelopment is almost the same as underexposure, except sometimes you can see the factory printing on the edge of the negative isn't as developed as it should be. Sometimes streaks are visible if you're WAY off like testing a new developer/process.

  10. #10
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    This article on "Assessing Negatives" is handy:

    http://www.ephotozine.com/article/as...negatives-4682
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

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