Datacolor User to User Support Group.

>Hey Paul,
>
>Thanks for the encouragement. I am glad to hear that you arrived at
>good profiles and found that all your gear was OK. With the variables
>of a new (and expensive!) monitor setup, and a new iteration of the
>program, it got confusing for me. I wonder why we are experiencing
>roughly the same color shift issues, manageable as they may be with a
>relatively consistent range of adjustments. On the other hand, though
>you have found that different levels of Magenta and Blue will put
>things right, the need for up to 5 Magenta and 12 Blue indicates what
>is to me a lot of Green/Yellow to compensate for. The down side of
>this is it can present the need for a lot of testing, which is what I
>bought PFP to avoid. I wonder if it is that Eizo and Lacie have
>similar methods of describing and arriving at neutral colors, and that
>these are different from the Colorvision models used in developing
>PrinFixPro? I look forward to a response from David (s) to get his
>take on this color shift issue and on my questions about using dual
>monitors on a Mac in my original post.
>

A couple of quick comments:

Calibrate your displays for D65, gamma 2.2. And when you view prints,
use a "daylight spectrum" light bulb, with a color temperature of 6500K,
to view them with. (Plenty of floor/table lamps sold this way, and you
can also get bulbs from GE, for instance, if you look through the product
list on their web site).

In PFP 2.0, we changed the slider range adjustments, so they're "half as
strong" as they were in the original 1.0 and 1.1.1 versions.

So an adjustment of 5 magenta in 2.0 is the equivalent of 2.5 in the older
versions; and 12 Blue is the equivalent of 6 in the older versions; these
are both very small adjustments; the numbers aren't as "big" as they seem
to be.

In terms of "neutral", what you can do to check the actual neutrality of
printing through your profiles, in terms of how the spectro sees color,
is this: after you've built a profile with all sliders at 0, (and this should
be a profile created from both a color target and the extended grays
supplement), take a grayscale image (for example, the B&W test image we
provide) and print it through the profile.

Then use the Measure tool in PFP and measure the grays that you've printed.
(For example, one of the solid gray patches at or near 50% gray).

See what Lab values the spectro reads. A "perfectly" neutral gray will have
a Lab where a = b = 0.0

That kind of ultimate perfection isn't going to happen, but you should get
a and b values that are close to 0. Regardless of what things look like
to your eyes, that's what "neutral" really measures as.

Best regards,

-- 
David Miller
Senior Software Developer, Digital Color Solutions
ColorVision