Re: Working color space of Aperture/Lightroom
Re: Working color space of Aperture/Lightroom
- Subject: Re: Working color space of Aperture/Lightroom
- From: Nov06 <email@hidden>
- Date: Sat, 28 Jul 2007 01:37:12 +0200
On 26.07.2007, at 02:59, Nov06 wrote:
I just tried it out in Aperture. Created a neutral gradient in PS,
working space set to Adobe RGB, saved as a tif, imported into
Aperture. RGB values are at no point equal. Using levels, eg,
shifts colors visibly.
I think I have to retract that statement. I either had soft-proofing
on or was using a gradient that had undergone some curve tampering in
PS before. Pure gradients, defined in sRGB, Adobe RGB or ProPhoto RGB
always show equal RGB values in Aperture.
Playing around around a bit more, I've got the impression that
converting between the standard (matrix?) color spaces like sRGB,
Adobe RGB, ProPhoto RGB, grey gradients always remain neutral (in
that R=G=B, ±1). Converting into the non-matrix RGB color space of my
printing lab, this is no longer the case.
That said, apart from concluding that Lightroom and Aperture use
"symmetrical" (ie, matrix?) color spaces internally, which was to be
expected, this grey test does not tell us anything.
Therefore, I repeated the test with magenta-green gradients. Defined
tiffs in sRGB, ColorMatch RGB, Adobe RGB and proPhoto RGB. Both sRGB
and and ColorMatch do have values of less than 255 when sampled in
Aperture. Both Adobe RGB and proPhoto have exactly (255 0 255) and (0
255 0), in Lab both have 83/-128/87 and 68/101/-51. One conclusion
therefore could be that Aperture uses internally Adobe RGB (or
something based on Adobe RGB having the same gamut). If a file with
colors outside Adobe RGB is imported it clips it to Adobe RGB since
the Lab values it display match those of the gamut of Adobe RGB.
However, upon exporting into ProPhoto, Aperture again remembers that
the original file had a larger gamut and produces again a file that
can fill out the gamut of ProPhoto.
Andrew, I say, so far all the evidence is supporting your notion of
Adobe RGB being the working space of Aperture.
Cheers,
Markus _______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden