Re: ICC Profile location for PS RAW
Re: ICC Profile location for PS RAW
- Subject: Re: ICC Profile location for PS RAW
- From: Roger Breton <email@hidden>
- Date: Sun, 02 Nov 2003 21:04:04 -0500
>
The conversions are hardwired into CameraRaw-theres no folder with
>
profiles. In practice, I find that the only controls in Camera Raw
>
that can't be replicated on the processed file are the color
>
temperature, tint, and exposure controls. If you set those and
>
convert to ProPhoto RGB, you can then convert to any space you want,
>
and the losses involved in doing so are trivial.
>
>
Bruce
I, too, have been a fan of ProPhoto to convert CameraRAW images from my
D100. I used to use sRGB for a while but then, I reason that ProPhoto suited
my style of working space better than sRGB since it is D50-based.
However, a recent assignment forced me to reconsider my choice of ProPhoto.
I was working on a project where I had to shoot romaine lettuce. I used
direct sunlight to shoot the lettuce. It gave a nice, crisp and bright light
-- as white as can be. I got gorgeous colors, rich greens. When I brought
the NEF file in CameraRAM, I left all the default settings intact, i.e. same
color temperature, exposure, etc. So the image went straight from capture to
ProPhoto, my choice of Destination space then. After some basic tnal
editing, I saved in PSD format for placement in InDesign. At the time of
output, the image was converted to US WebCoated SWOP v2, RelCol, my default
CMYK Working space, in ID's Print dialog box. Later, I exported the document
to PDF and converted the same way to send it to my service bureau. The image
then ran on an Indigo UltraStream 200 press and the same time I ran some
CMYK characterization targets for developping a custom profile. When I got
the prints back from the Indigo, I must say I was quite impressed with the
overall color appearance of the lettuce. But when I started to compare the
print to my ProPhoto image on my CRT I started to notice some discrepancy.
When I finally finished my Indigo custom profile and converted the orginal
image from ProPhoto to myCustomIndigo profile, RelCol, in Photoshop, part of
the converted image turned to yellow, sort of like maple leaves in fall. In
must say only the most most saturated greens in the lettuce turned that way.
The rest of the image was in-gamut. I could not reconcile this result with
the fact that US WebCoatedSWOPv2 seem to have retained these saturated
greens alltogether! So I started to search for an explanation. It turned out
that when I assigned my CustomIndigo profile to the US WebCoaredSWOPv2 CMYK
image, there was a perfect match between my CRT image and the Indogo print,
as viewed in my GTI booth. So myCustomIndigo profile was good. The problem
was still when I tried converting from ProPhoto to myCustomIndigo.
So I decided to analyse the problem with Monaco's excellent GamutWorks. And
when I opened my Lettuce image tagged with ProPhoto and compared with
myCustomIndigo profile, it was clear to see that some strong gamut clipping
was occuring using RelCol. I decided to stay with RelCol. So, I decided to
experiment with AdobeRGB and sRGB as source spaces for my conversion by
pre-converting from ProPhoto to AdobeRGB and sRGB. Guess what: converting
from AdobeRGB and sRGB retained more and more of the original saturation of
the green color of the lettuce leaves! One possible explanation is that
converting from ProPhoto to AdobeRGB and sRGB resulted in gamut clipped
conversions and a loss of saturation in the first place. So, no wonder when
I converted from these two smaller color spaces the saturation of the green
was retained more and more.
To make a long story short, I am not sure I will retain ProPhoto as my
"standard" Destination space out of CameraRAW. Did you see how large is
ProPhoto as opposed to AdobeRGB and sRGB: it's huge!
I am learning everyday.
Roger Breton | Laval, Canada | email@hidden
http://pages.infinit.net/graxx
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