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Author Topic: Anyone have a Kodachrome 64 slide of a Macbeth Color Checker I can borrow?  (Read 6565 times)

AFairley

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I'm digitizing all my old Kodachromes using my DSLR (if I want to print one, I scan it with a CoolScan, but that's WAY too slow to do all of them).  However, the colors I am getting are noticeably different that the colors on the chromes.  I wonder if anyone has a Kodachrome of a Macbeth Color Checker I could shoot and use to create a custom ACR profile for the chromes with the Adobe app.  I know I shot some back in the day for references, but I just cannot find them now.   I would pay for Priority Mail to me, keep the chrome about a week, and mail it back via Priority Mail.

Thanks.
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dmerger

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Dean Erger

AFairley

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janster

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Re: Anyone have a Kodachrome 64 slide of a Macbeth Color Checker I can borrow?
« Reply #3 on: February 20, 2012, 05:50:15 PM »

I don't think anyone's kodachrome slide of a ColorChecker will make you happy. It probably wouldn't even be a ColorChecker anymore because of the kodachrome "reproduction". The spectral values would have to differ vastly from the original reference values the ACR uses to create a profile and thus it's of no use for a valid ACR profile.
I think you will most probably get much improved results colorwise if you can simply find out the exact color temperature of the light source you're using when digitzing the slides with your SLR. Once you know the exact color temperature you can use it as a white balance setting during the raw conversion.
Optionally, if the color temparature of your light source is anywhere near the D50/5000K and since you are operating in a rather stable light situation when digitizing slides with an SLR, you could use the afore mentioned kodachrome it8 target, accompanied by the real spectral reference data, to create a genuine input camera icc profile with a third party profiling software capable to create decent camera profiles. Haven't tried this myself before but theoretically this setup should provide for the most accurate color reproduction. Best, JAN.
« Last Edit: February 20, 2012, 05:52:43 PM by janster »
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Iliah

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Re: Anyone have a Kodachrome 64 slide of a Macbeth Color Checker I can borrow?
« Reply #4 on: February 24, 2012, 09:04:30 PM »

You can try with CC24 shot on any Kodak slide film actually, given it is exposed and processed carefully. Out of curiosity, how close are CoolScan resultsto the actual colour on the film?
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AFairley

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Re: Anyone have a Kodachrome 64 slide of a Macbeth Color Checker I can borrow?
« Reply #5 on: February 27, 2012, 01:07:56 PM »

You can try with CC24 shot on any Kodak slide film actually, given it is exposed and processed carefully. Out of curiosity, how close are CoolScan resultsto the actual colour on the film?

The CoolScan colors are accurate (moreso than my DSLR), but somewhat desaturated.  The CoolSan has a separate setting for Kodachrome.

On a related note, on Saturday I found my ColorChecker Kodachromes and Ektrachromes from the 1980s, and so was able to proceed.  However, I have not yet been able to use them to create an ACR camera profile for DSLR "scanning."  The DNG editor profile-maker module reported that one of the grey squares had a color cast and ordered me to reshoot.  It is true that back in the day I was always fighting a tendency to a magenta color cast in Kodachrome 64 professional back then, the the extent of testing rolls of film and buying and freezing multiple bricks of emulsion lots that showed it less, and this shows in the chromes.  Since I also have Kodachrome and Ektachrome grey card and step wedge reference shots from back then, I will try reshooting with a custom white balance, and if that does not make the DNG editor happy, will reshoot gelling my light source (TTL strobe) to neutralize the chrome's native color cast.  So more to come.....

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Iliah

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Re: Anyone have a Kodachrome 64 slide of a Macbeth Color Checker I can borrow?
« Reply #6 on: February 27, 2012, 02:11:29 PM »

 If CoolScans are accurate, scan your CC24 and make a profile link between the shot of CC24 and colour-corrected scan of CC24.
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