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  1. #21
    Bob Carnie's Avatar
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    Opps
    forgot to mention , when cutting in the dark with a olfa blade, make sure you count all your fingers and thumbs as well wear clothes for that other appendage.

  2. #22
    Lopaka's Avatar
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    Thanks for the info, Bob. Will revisit the topic in a few months after I
    do some work with the less expensive paper version of FCA.

    Bob
    "I always take a camera, That way I never have to say 'Gee, look at that - I wish I had a camera'" -Joe Clark, H.B.S.S.

  3. #23
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    Both the Fuji and Kodak papers are just fine.

    Wilhelm's stability data are derived from using a higher intensity lamp than Kodak uses and the intensity is closer to what Fuji uses, therefore Wilhelm's methods more closely match those of Fuji.

    The higher intensity lamps used for fading will simulate most open office areas and building foyers. The lower intensity lamps simulate most homes and museums which use lower intensity lamps for display. Humidity and heat in dark keeping are often misleading depending on how prints are kept. Stacked prints will fade in the dark differently than loose prints and framed, glassed prints fade differently than unglassed prints.

    Kodak Endura paper will last at room temperature for at least a year with little change. I have done that.

    PE

  4. #24

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    Quote Originally Posted by Chan Tran View Post
    I use Supra Endura paper also. I for now using a film scanner to determine color balance and exposure. It works quite well.
    I'd be interested in hearing how you do this. Do you have special software that spits out exposure and filtration values, or have you figured a way to convert from values provided by your standard scanning software to get good filtration and exposure settings?

  5. #25

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    Quote Originally Posted by srs5694 View Post
    I'd be interested in hearing how you do this. Do you have special software that spits out exposure and filtration values, or have you figured a way to convert from values provided by your standard scanning software to get good filtration and exposure settings?
    This is a rather long post and it is about using a film scanner to determine filter settings and exposure for color printing with an enlarger. That is the old fashion way.
    The color balance of a color negative film changes significantly from batch to batch and also as unexposed film ages. Unless you buy film in bulk and keep them refrigerated until ready to use, each roll of you film will need a different filter pack when you print them. A color analyzer helps but it never really solved the problem because color analyzer either works on a known color on a negative like a gray card or skin tone or assuming all negatives integrate to medium gray. We don't always have a known color in every shots that we made nor that our photographs would intergrate to a medium gray. The idea of using a film scanner to solve this problem had been in the back of my mind for a long time and now after spending quite some time experimenting and studying the possibility I have come up a way to do just that.
    1. Make a negative of a gray card that completely filled the frame. The gray card should be evenly lighted with a daylight balanced light source (like the sun).

    2. By trial and error (oh yeah, can't really get away with this) make a print that matches the real gray card record the filter settings, lens aperture used and exposure time.

    3. Using a film scanner (I use the KM Dimage Dual Scan IV) and scan the negative with manual exposure settings. Adjust the settings so that the scan gives the RGB values of around 120, 120, 120. The RGB values would vary somewhat around the image but try to get the average. The scan should look very close to the gray card. Most scanner would have 4 sliders for exposure setting. One for overall exposure and one each for each of the red, green and blue color channel. They are calibrated in EV generally. Record the settings as only in 3 values by adding the value of the overall exposure with each of the color channel. For example if you get like +1.2 for exposure, +0.1 for red, -0.5 for green and -0.3 for blue then record them as +1.3 for red, +0.7 for green and +0.9 for blue.

    4. Scan the negative that you want to print also with manual exposure settings. Adjust the settings until the image looks good on your monitor in term of both brightness and color balance. Record the settings the same way you did for the gray card negative.

    5 Subtract the settings for the gray card negative from the negative you would like to print. Multiply the difference in the red and blue channels by 30 and the green channel by 25. By theory they all should be muliplied by 30 but experimentally I found for some reason the green channel needs a smaller multiplier. The results will be the amount of filter you would need to add or subtract from the filter settings for the gray card negatives.

    I understand that my post is a very abreviated procedure. If you have any questions please let me know.

  6. #26
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    Quote Originally Posted by Chan Tran View Post
    The color balance of a color negative film changes significantly from batch to batch and also as unexposed film ages.
    This is a myth.

    Color negative film balance is as constant over the years as color reversal film! Changes with keeping are similar to what is seen with reversal film, but in general are less deleterious to the imaging than with reversal films.

    These statements are based on 32 years in the business and tests of films made over a 50 year period. I can print 50 year old films at about the same balance as modern films within about a 10 Y.

    This refers to Kodak film primarily, but the Fuji films that I have tested fit closely into this category. Agfa films generally have fallen outside of this for both color balance and changes with keeping.

    PE

  7. #27

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    In my little experience there is a change in color balance if it takes too long between exposure and development (months). This has happened to me in the same roll, being left in the camera for long time with some exposed frames, then expose the rest of it. (pictures with similar lighting conditions)

    Francisco

  8. #28

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    Quote Originally Posted by fdisilvestro View Post
    In my little experience there is a change in color balance if it takes too long between exposure and development (months). This has happened to me in the same roll, being left in the camera for long time with some exposed frames, then expose the rest of it. (pictures with similar lighting conditions)

    Francisco
    I wonder if this was due to other reasons. My wife takes many months to use a roll of 24. Typically the first shot is the New Year party and the last the Christmas day celebrations and I have never seen a change in colour balance.

    No doubt others will agree or disagree, hopefully with reasons.

    pentaxuser

  9. #29
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    The latent image of a color negative film and a color reversal film are about equal for stability. The color negative is actually a bit better due to the fact that any changes are able to be damped out in printing.

    I would say that at normal room temperatures, the images on exposed film should last for at least a year with no significant change as far as amateur purposes are concerned.

    The discriminating professional should process the film as soon as possible and keep the film as cool and dry as possible.

    PE

  10. #30

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    The changes I have experienced are very small and appreciable only in a contact sheet or if you don't change filtration in the enlarger.
    Also, again in my experience, professional films like portra 160 nc are more sensible to this (the old Kodad vericolor was the most sensible). It hasn't happened to me with consumer grade film.
    Temperature and humidity were above recomended, so they might be factors to consider.

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