Datacolor User to User Support Group.

CDT and David - thanks for response. I find the it does not seem to 
affect the overall reading as you indicate.

--- In colorvision_group@yahoogroups.com, CDTobie@... wrote:
>
> 
> In a message dated 1/11/07 10:43:35 AM, doug@... writes:
> 
> 
> > 
> > I have the GO setting on the Epson R1800 driver set to AUTO - I 
printed
> > the targets from PrintFix Pro 2.0 software.
> > 
> > Any thoughts out there?
> > 
> 
> Well, my main thought is that way too much consideration has been 
given to 
> GLOP and its effects on profile building already. GLOP is mainly to 
fix an 
> optical effect (I'm tempted to say optical illusion <G>) in which 
inked and uninked 
> sections of the image, at close proximity, under extremely low 
light angle, 
> show an unpleasant difference in surface reflectivity. 
> 
> Patchreading devices work at a very precise 0/45 configuration 
where all the 
> light is supplied at 45 degrees to the surface, and all 
measurements occur at 
> zero degrees (perpendicular) to the surface (or in rare cases, the 
reverse). 
> So gloss differential won't even be perceived by a spectro, and the 
angle is 
> too tight. The white patch will, theoretically, read as a slightly 
different 
> white when GLOPped or not GLOPped, but if you put an image with 
GLOP on the main 
> image, but not the border, in a light box where the lightsource is 
45 degrees 
> from the image plane, and your eye is perpendicular to the image 
plane, and 
> attempt to distingush where the edge of the GLOP zone is, and what 
difference 
> there is in the color of white in the two sections... well, I don't 
think you'll 
> see much that would concern you.
> 
> Other details of the profile calculation process minimize the 
difference even 
> further. So overall, my level of concern about whether GLOP is or 
is not used 
> in the profiling process is pretty low. Whether its used in a given 
print is 
> a matter of how the print will be presented and displayed; if low 
level light 
> and low level viewing angles may occur, then GLOP is a real 
benefit. But in a 
> step-back matting system, under glass, on a wall with proper 0/45 
lighting 
> viewing angles (as in a gallery), its as moot for viewing as it is 
for profiling.
> 
> C. David Tobie
> Product Technology Manager
> ColorVision Business Unit
> Datacolor Inc.
> CDTobie@...
> www.colorvision.com
>