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Re: [colorvision_group] White/Balck Point setting

2009-02-14 by Nathan Gutman

Thanks, can you also amplify how does this apply to calibrating a projector?
Nathan

Cdtobie wrote:
With CRT displays, there were controls for both contrast and brightness, and the most effective way to avoid clipping at either end while doing a visual, not measured calibration, was to adjust until the four squares were visible.�

For LCDs this is seldom an issue. First, on less expensive displays there may be clipping at all settings. And with the types of controls on many LCDs, clipping may not occur at any setting. Besides, most LCDs have no control to adjust the blacks, and whites on them are so bright that luminance is not set to just below clipping, it's ideally set way down from full brightness, through a targeted white luminance value. Targeted white and black luminance values are measured with the Spyder, not set visually. ��

To put of much more simply: if you don't like making visual adjustments, select measured, not visual mode. Then your setting will not come from the four visual squares, but from Spyder measurements you take later in the calibration process. � ��

C. D. Tobie
Global Product Technology Mngr.
Digital Imaging & Home Theater
Datacolor.com

On Feb 13, 2009, at 8:24 PM, Nathan Gutman <nzgutman@sbcglobal.net> wrote:

I am still learning... learning...
Spyder hardware is supposed to eliminate the visual judgment needed when using calibration software such as Adobe Gamma or QuickGamma.
But when using Spyder I am asked to visually inspect four white squares and four black squares and adjust monitor brightness and contrast accordingly.
Isn't this predicated on the visual acuity of the observer?
Can someone please explain?
Thanks,
-- 
Nathan Gutman
=

-- 
Nathan Gutman

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