Re: Digital Camera Profiling
Re: Digital Camera Profiling
- Subject: Re: Digital Camera Profiling
- From: Terry Wyse <email@hidden>
- Date: Mon, 24 Sep 2001 10:20:32 -0400
on 9/24/01 9:31 AM, Steve Lehning wrote:
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In working with digital photographers when
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lighting conditions change constantly, the positioning of product changes
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and any other variables one can think of change, it seems to me that you
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would almost have to build a new profile on every camera shoot. By saying
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this I dont meen on every click of the camera, but on every product shoot
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where the lighting and the conditions remain the same through out the day.
There's some disagreement on this, but I would argue that as long as the
profile represented the full range of the camera AND the lighting
TEMPERATURE was constant, then a single profile should work fine even if the
lights are repositioned for a different shot.
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Especially on some studios where there are alot of windows which bring in
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natural lighting into the senario, high noon on a sunny day verses a night
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or a dull overcast day.
Well, now you're talking differences in color temperature which throws the
profile out the "window"!
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The reason for my frustration comes in when we had
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done a test profile on a camera shot one day, which turned out O.K. Then a
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week later we had gotten the rest of the job in on disk with about 15 images
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using the supposed same lighting set-up, but shot a few days later.
My guess is that they're altering the gray balance compared to how the
profiling target was captured and/or they're manipulating the gradation/tone
reproduction curves during the capture/prior to applying the profile in
Photoshop.
This is probably going to really pain the photographers you're working with,
but the only way it can really work is that they capture the images using
the same software settings that were used to profile the camera in the first
place. This usually means A) using a LINEAR tone curve with NO adjustments
and B) doing a simple gray balance adjust using a standard gray scale target
and on the same step of the gray scale each and every time.
Terry
_____________________________
Terence L. Wyse
Color Management Specialist
All Systems Integration, Inc.
http://www.allsystems.com
email@hidden
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