Datacolor User to User Support Group.

On Aug 10, 2009, at 6:02 PM, Robert Peirce wrote:

> Thanks for the tip on the tools menu.  I never used that.  I took a  
> look at my calibration and got LabL=106.945
> a=-2.245
> b=-21.070
> and
> K=6529
>
> This is on a MacBook Pro set at 6500K and 2.2G.  I can't comment on  
> the a & b values; they seem to be close to yours.  However, your L  
> values seems to be very low, especially for the Eizo.

Eizo's run dimmer than most other displays, as they are intended for  
low light matching for serious work.
>
> Shouldn't pure white be a=b=0?  < 5 seems like it oug ht to be okay,  
> but 20 seems to be pretty high.

In this case Luminance really means Candelas/MeterSquared, so values  
well above 100 are common; values above 300 are possible, but  
certainly are not recommended for color managed work.
>
> I normally run at 5400K because it matched my printer better.  On  
> that I got:
> L=103.955
> a=-1.910
> b=-6.921
> and
> K=5473

Correct; slight luminance drop from the channel corrections, and a  
change in b*; thats what a lower color temperature means: less blue.
>
> For other temperatures, a seems to stay around -2, but b grows:
>   -2 @ 5400
> -13 @ 5800
> -18 @ 6200
> -21 @ 6500
> I have no idea what that means, if anything.

It means you are making your screen less blue, which is what dropping  
the color temp does.

C. David Tobie
Global Product Technology Manager
Digital Imaging & Home Theater
CDTobie@...


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