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Thread: Color anomalies, Imacon 848+Portra 160NC?

  1. #1

    Color anomalies, Imacon 848+Portra 160NC?

    I'd been scanning Portra NC 160 on a flatbed scanner, but today tried some scans with an Imacon 848. My intention was to do minimal processing in FlexColor – I thought the FlexColor Portra 160 NC profile would yield adequate results for later processing if I just set the histogram correctly & then post-processed later in LR/PS.

    But the Portra profile didn't seem accurate enough to allow such a simple treatment. The color was less accurate than my flatbed scans. I was especially bothered by overwhelming greens, when other colors came close to what I expected. I had trouble correcting them either with the FlexColor software, or later with PS. The scanner's owner checked me out, & we saw no incorrect settings.

    --Have others seen color anomalies with this combination of film & scanner profile?

    --I didn't have time to check & see: does the FlexColor RGB Standard profile perhaps give better results with Portra 160 NC?

    (Other than this color problem, I was a happy scanner. With sharpening/texture set at -120, the images looked much clearer than flatbed scans, yet didn't have the over-sharpness of FlexColor's default sharpening. In this respect they looked very 'photographic' to my eyes, which are still calibrated to 20th-century photo norms.)

    Kirk

  2. #2
    Gilbert Plantinga
    Join Date
    Sep 2007
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    57

    Re: Color anomalies, Imacon 848+Portra 160NC?

    The bundled film settings for negatives (and they are settings or "Setups" in Flexcolor parlance, not profiles per se) in Flexcolor, at least the ones I've tried, suck so I've always created my own. Bear in mind that to do this right you need to make separate setup files for different kinds of light, sunny, cloudy etc., and you'll still need to do some tweaking to get the color balance right. Color negative is a subjective thing. Here's how to do it: You need three sheets of film and a Gretag color checker or similar target (best not a Kodak gray card, they're not really neutral). Develop one sheet unexposed, shoot one sheet of the target exposed per an incident meter reading, and shoot one sheet of the target overexposed by 6 stops. In Flexcolor choose any color negative setup, expand the histogram window to show all three channels and move the endpoints on each channel to 0 and 255; set all three midpoints to 127. Pre-scan the unexposed sheet and sample the image with the black eyedropper -- this sets your base+fog+orange mask and balances your shadows. Pre scan the overexposed target and sample the white square on the color checker -- this does the same thing for your highlights. Then pre-scan the properly exposed target and set the neutrals with the middle eyedropper on whichever middle gray patch gives the best looking color balance. Finally, open the Setup dialog, check the CC tab and make sure that all of the color corrections and the saturation box are zeroed out, and save your setup. You can also dial in your preferred sharpening and flextouch (if you use it) settings as defaults. Hope this helps.

  3. #3

    Join Date
    Sep 2007
    Location
    Brooklyn, NY
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    275

    Re: Color anomalies, Imacon 848+Portra 160NC?

    The best way I have found the scan color negs with the imacon is to make sure that there are no clipped areas on the histogram and do all your corrections in photoshop. This gives you a scan with as much information as possible. Or, to take it one step further, scan it as a FFF file and do the inversion and all the corrections in photoshop.

  4. #4
    mortensen's Avatar
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    Jul 2009
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    Copenhagen, Denmark
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    451

    Re: Color anomalies, Imacon 848+Portra 160NC?

    Quote Originally Posted by J. Gilbert Plantinga View Post
    The bundled film settings for negatives (and they are settings or "Setups" in Flexcolor parlance, not profiles per se) in Flexcolor, at least the ones I've tried, suck so I've always created my own. Bear in mind that to do this right you need to make separate setup files for different kinds of light, sunny, cloudy etc., and you'll still need to do some tweaking to get the color balance right. Color negative is a subjective thing. Here's how to do it: You need three sheets of film and a Gretag color checker or similar target (best not a Kodak gray card, they're not really neutral). Develop one sheet unexposed, shoot one sheet of the target exposed per an incident meter reading, and shoot one sheet of the target overexposed by 6 stops. In Flexcolor choose any color negative setup, expand the histogram window to show all three channels and move the endpoints on each channel to 0 and 255; set all three midpoints to 127. Pre-scan the unexposed sheet and sample the image with the black eyedropper -- this sets your base+fog+orange mask and balances your shadows. Pre scan the overexposed target and sample the white square on the color checker -- this does the same thing for your highlights. Then pre-scan the properly exposed target and set the neutrals with the middle eyedropper on whichever middle gray patch gives the best looking color balance. Finally, open the Setup dialog, check the CC tab and make sure that all of the color corrections and the saturation box are zeroed out, and save your setup. You can also dial in your preferred sharpening and flextouch (if you use it) settings as defaults. Hope this helps.
    Now that was really helpful! Thanks - I'm sitting in exactly the same problems.

  5. #5
    mortensen's Avatar
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    Re: Color anomalies, Imacon 848+Portra 160NC?

    Btw. Gilbert, before I have the time to do as you write... could I get your histogram readings from your sunny and cloudy portra setup??
    If it's not too time consuming for you, that is.

    ... it would be such a time saver!

    At the moment, when I rent the scanner, I use fully expanded histograms on all channels and have midpoint 70 for red, 110 for green and 115 for blue. It gives a relatively precise scan for most images, but they could be less foggy without clipping and I occasionally have problems with green colour cast.

    thanks,
    lars

  6. #6

    Join Date
    Feb 2008
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    397

    Re: Color anomalies, Imacon 848+Portra 160NC?

    If the colors are off after the inversion and dark(most important) & white point adjustments, then the color profile of the scanner is not good. If that's the case no readings from other scanners will help much.

    SergeyT.

  7. #7
    mortensen's Avatar
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    Re: Color anomalies, Imacon 848+Portra 160NC?

    okay... I should probably go read a little in the imacon user group

  8. #8

    Join Date
    Feb 2008
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    397

    Re: Color anomalies, Imacon 848+Portra 160NC?

    I did not mean that, sorry. My comment was related to the following question: "could I get your histogram readings from your sunny and cloudy portra setup?? "

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