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My HS10 has 635hrs on it.. with CC40R filter via HTPC. I find that increasing contrast in the projector and/or the overlay setting causes the picture to go yellowish. I also need the gamma pretty high around 1.2-1.45 latest ATI drivers to see shadow details.


I would like to have it maintain the same whiteness while increasing contrast. Is this normal for picture to go yellowish? or is my bulb ageing??


I find LOTR doesn't look that great with this projector as the film uses a very muted color pallette. Has anyone noticed this?
 

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You're most likely turning up the contrast too high and crushing whites. Since the bulbs most consumer PJs use are red-deficient, when they run out of gas the picture loses red. Hence the colors you see.


To set it properly, you need a test disc; or in a pinch you can just put up a very bright white picture and turn the contrast down until the color balance looks even again.
 

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You are throwing away 40% of the light output of the projector by using the ND filter. It sounds like you are then trying to compensate for the low light output by cranking the contrast and gamma. I would suggest changing to a lower numbered ND filter (CC30R? CC20R?) and re-calibrate.
 

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Huck is right on - as the bulb ages and dims, the most optimum filter changes from a CC40R to a 30R or 20R, and you will have to compromise on the CR and the total overall luminance.


The reason the white turns yellow is because the blue colour is the limiting colour due to the use of the CC filter. If you do the same thing without the filter, white will turn "cyan" in colour as you crank up the Contrast setting because the limiting colour then is red.


This is completely normal and an artifact of the natural colour of white of the bulb used in projectors, which don't have sufficient red in them in their natural in colour-corrected state.


Dave
 
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