Why are pure colors so desaturated when applying printer profiles?
Why are pure colors so desaturated when applying printer profiles?
- Subject: Why are pure colors so desaturated when applying printer profiles?
- From: email@hidden (Scott Kilbourne)
- Date: Fri, 11 May 2001 09:55:08 -0400
I must be missing something basic here, please help.
BACKGROUND
We're running Gretag-Macbeth's color management stuff - ProfileMaker for generating
profiles and Iqueue as a color server connecting us to all our output devices.
I've put together a test pattern in Photoshop 6.01of some nice scans, an IT8 and
some pure color patches (RGB and CMYK each at full intensity). We're working in
Adobe RGB as our default color space.
PROBLEM
In printing to our Fuji Pictro 4000, we're getting very good results on the scans
and IT8 part of the test target through the profile, both in converting to profile
in Photoshop and in letting Iqueue apply the profile - BUT - the RGB patches
desaturate dramatically when the profile is applied (R=253,83,58 G=102,254,90
B=52,87,238). On test prints that use the profile, the RGB patches print on our
Fuji as pukey orange, mashed peas green and a violet. the rest of the print looks
great. When we send the test target still in AdobeRGB to the printer, we get a
slightly cool version, but with much more saturated RGB patches.
COMMENTS
Once I saw this, I tried converting our test pattern to a number of different
profiles. Converting to ColorMatch left the colors saturated. Converting to other
printer profiles, including ones that shipped with Photoshop, however, showed the
same desaturation problem on the RGB patches. BTW, the CMY patches also
desaturate, but not as badly. Results do not change significantly when changing
rendering intent from perceptual to absolute or relative colorimetric.
QUESTION
What am I missing here? The Fuji is capable of much more saturation than the
profiled prints use. The scanned part of the test target adjusts only subtley when
printer profiles are applied, but the pure colors jump dramatically. I could
understand if this was gamut clipping, but why does it clip to so far inside the
available gamut of the printer?
Seeking the wisdom of the group...
-Scott Kilbourne
Biomedical Communications
Wake Forest University School of Medicine