Andy Johnstone wrote:
(clip)
OK,
I use apple RGB colour space for most images not "adobe 1998" sorry. Dunno how that slipped out....
The scans are in "nikon apple rgb 4.0.0.3000" colour space.
I have "Adobe ACE", Apple CMM, Heidleberg CMM and apple Coloursync engines available to me in PS. Anyone have an idea which is preferred and why?
The AdobeACE, while only available in Adobe applications, is the only CMM which support BlackPointCompensation - an essential tool for Relative Colormetric conversions. This ability makes the AdobeACE CMM the preferred and most flexible and powerful CMM to use.
Outside of Adobe applications the AppleCMM on Mac and the KodakCMM and/or LinoCMM in some cases on PC are the basis of OS system wide engines. There are not great differences in the Apple/Lino/Heidelberg/Kodak CMMs, though some might argue otherwise. Each generates a mild scum here and there under differing circumstances, as will all CMMs when dealing with third party calls. The general rule of thumb is to use the CMM commanded most by your workflow; i.e. if you are using a whole whack of Heidi front end profiling and image processing software then it makes sense to use Heidi...etc., etc...
If you are using Colorsync and have several CMMs available and (under v2.6 to v3.0.4) your CMM is set to Automatic then calls made to Colorsync will utilize the available default CMM of the profile or application making the call. If the default CMM is not available AppleCMM becomes the default.
As for AppleRGB (gamma 1.8, 6600k) small space some call "safe."
ColorMatchRGB (gamma 1.8, 5000k) small space but conforms to standardized viewing conditions.
AdobeRGB (gamma 2.2 6600k) is somewhat larger but can present out of gamut colors to unseasoned recipients.
sRGB (gamma 2.2, 6600k) small space with some tonal compression.
The bottom line is: all of these spaces are valid. If the file is accurately tagged in an actual workspace the file is a workable file for most applications and/or conversions. The premise of working and archiving in as large a space as possible is a good one, though the reality of handing off files in a safe space is also a wise one. We tend to work and archive in AdobeRGB, but hand off in sRGB to avoid calls from non-CM folks running a host of applications which tend to default to sRGB anyway.
Professionally I work in AdobeRGB. Though I prefer ColorMatchRGB as a 'safe' hand-off space...but that's just because I'm an old RadiusPressView hack.
Hope that helps....
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