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Discussion Starter · #1 ·
I now have a 75u (love it - even with a Walmart $6 white sheet for a screen - - not too far off the dalite matte white sample I have).


I am trying to calibrate the basics using VE.


Black level is easy using any/all of the pluge patterns.


White level is the problem - the blooming/distortions based setting will not work as LCD is essentially impervious to this.


So - I found some test patterns on the disk with increasing grey scale across the screen and adjusted it so that there seemed to be a fairly even increase from white towards black. At the default setttings, white saturated too early (and so did black).


Once 'calibrated' this way, the default setting just look washed out and lacking the high and low brightness detail and 'splash' now acheived. (I though it looked great before this calibration - can't wait to set things up for real - screen, mount, some more light control, etc. )


Thoughts? Comments? Other Methods?


What settings are people ending up with on this unit?
 

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I sort of went through the same thing, using the THX setup on T2:UE.


When the grey scale was presented, the last three bars were all black. As I adjusted contrast, the bars came into view, such that I had varying degrees of grey all the way from white to black. But, when it was all said and done, I don't know that I liked the picture any better.
 

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On my 75U I adjust whites so that they aren't slightly green. I run in standard display mode with standard colortemp with a Hoya FL-Day filter. If I crank contrast way up the whites take on a definite green shade. This is really obvious on faces where bright hightlights show up greenish/white against the usual fleshtones. I used both solid white and greyscale patterns from Avia to judge the 'coloration' of my brightest whites .


I've thought about trying Guy Kuo's method involving filters, a photocell, and a voltmeter to figure out where the LCD panels start clipping for white but I've been too lazy and eyeballing it has worked well enough.


robertmee -- did you really mean to write that you used the 'contrast' setting to up the brightness on black bars? If so, that's not what you want to do. You should use brightness to change black level and contrast for white level. Using contrast to up the black level could really leave your picture screwy. (yes, screwy -- a fine technical term)
 

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Unlike VE, Avia has patterns which allow you to precisely set the peak white level (contrast) just below the point of clipping.
 

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Quote:
Originally posted by hoxford



robertmee -- did you really mean to write that you used the 'contrast' setting to up the brightness on black bars? If so, that's not what you want to do. You should use brightness to change black level and contrast for white level. Using contrast to up the black level could really leave your picture screwy. (yes, screwy -- a fine technical term)
Now that you mention it, I'm not really sure. I went through it rather quickly before a movie showing that night. Since then, I've packed the PJ back up while I finish the construction in my basement. I did whatever the THX setup recommended when it showed the grey bars. I can't remember now if it was contrast or brightness.
 

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Quote:
Originally posted by Den
Unlike VE, Avia has patterns which allow you to precisely set the peak white level (contrast) just below the point of clipping.
But clipping can happen in more than one place on a digital PJ. I use Avia and long before the level is high enough to clip the white bars on that test pattern the 'color of white' becomes skewed because my red panel is clipping (even with an FL-Day filter). That test pattern is most useful to me for setting the white level on my HTPC. That way I can be sure I'm driving the PJ with a signal that is just below clipping. Then I adjust the PJ so that my white is actually white and all is well.
 

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Sure, but the alignment procedure is really the same whether CRT or digital display. You are running out of red and the symptom is "red clipping" or excess green; many CRT PJs run out of blue first. The point is (and you have already leanred) that contrast and black level setting are very much part of the iterative gray scale adjustment procedure.


But I think I'd go nuts adjusting gray scale on both an HTPC and the projector at the same time! Are you adjusting the RGB levels on the PC to overcome some limitation when adjusting only the projector?
 
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