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Join Date: Oct 1999
Location: NewPort, VA
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For PC DVI that is correct - if you have DisplayMate on your computer - look at your color ramps - the bright colors will be banded into a solid color rather than a range of bright colors. The reason is that Infocus is optically calibrated at D65 (within manufacturing tolerances) - unlike other projectors that are digitally calibrated to cut back from their optical calibration of 9000-1100K.
Since lamps are usually red limited - if RGB are clipped 100 IRE becomes tinted Cyan. I find the closing chapter of SeaBiscuit a good one for checking out white highlights - also any snow, cloud scenes. There is really not a good RGB range pattern on DVD yet - DisplayMate claims to have one in the works!
For Video DVI you have headroom/footroom remaining in the signal itself so as to stretch the range out on the projector (which is what the 66/39 does to regain contrast/brightness)
Most calibrators trained on CRT are unaware of this - just crank up the guns to get more juice. And even other digital projectors always have more Green/Blue available from the unfiltered lamp. But since Infocus colorwheel is designed for D65 - there is not more Green/Blue to tap into (less space on colorwheel) - so they will clip as well as Red (which is much of the colorwheel to get a Cyan lamp down to D65). They do teach at ISF to monitor colortemp at 100IRE because many displays will go south on colortemp - you are supposed to adjust so it tracks all the way across - and not just calibrate at 80IRE. Some calibrators may like to pump up the brightness/contrast numbers by mistracking highlights - which I find annoying!
Any other projector optically filtered for D65 will have the same problem. I think Sharp and Marantz are in this category - but there was a good thread on D65 spec vs. design vs. marketing and nobody else really contributed their knowledge!
Five years ago I sent my Runco out for professional calibration and it came back with the top third of reds all the same shade. I ended up buying into ColorFacts PowerBuy on AVS to fix it myself. Interesting how things turn out! But this is one of the reasons I try to stress this on the forum -calibration should not be a secret society - the more constructive criticism out there the better everyones displays can get. Either thru individual calibrators or even manufacturers catching a clue at doing it right. Everybody always has something more to learn!
For analog inputs I would have to check the behavior on individual systems - problem is the lack of a good RGB ramp test pattern. My thinking is the circuit flow goes ADC adjustments, color saturation/tint, then RGB - so it seems RGB would be limited because the data is digitized by the time it gets to those controls - but if there is maybe headroom left due to low voltages it might not be a problem. Because of this lack of RGB ramp test pattern I tend to use a little over on one color, then a little under on the other colors to minimize wild swings on anyone one color.
I am sure there might be a pattern buried on AVIA PRO - just have not looked deep enough.