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Discussion Starter · #1 ·
I know it's not for correcting red push and is for the greyscale, but when calibrating with Avia i lowered the color saturation to 0 and noticed when my screen is black and white the step blocks had a bit of a red tint to them. I lowered RCUT by about 10 with the color set to 0 and that really improved the redness a bit. Keep in mind i have no professional test equipment for greyscale but i don't think i needed any to notice the red tint when my screen was black and white. Only thing i'm concerned about is would what i did mess up the entire greyscale once i boosted the color saturation back up from 0? Should there be a little bit of a red tint in the greyscale?
 

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Nope, there shouldn't be any red tint to the gray scale patterns. I doubt if you've "messed up" your grayscale, since with a noticeable red tint it was FUBAR to begin with, but you can definitely adjust by eye for best-looking gray. To get to the recommended D65, you do need some form of instrumentation or an optical comparator. Just be aware that the cuts and drives actually have an effect on both ends of the gray scale. On my Mitsubishi CRT RPTV, for example, lowering a color's cut boosts its drive. On other makes, lowering a cut may lower the corresponding drive. Using AVIA's crossed-step scale or crossed-ramp patterns can help you see what's happening as you make changes. AVIA's grayscale patterns are known to have a tiny amount of magenta tint in the darker grays, but this shouldn't be visible. I do recommend you make these adjustments with the room as dark as possible, as other light sources or colors around the set can affect your color perception and thus your results.



Oh, BTW, if you're feeding your display via component from your DVD player, you can get a pure black-and-white signal and knock out the magenta contamination by disconnecting the red and blue component cables. Some displays (I don't remember which right now) don't act as you'd expect when color is decreased and actually make grayscale patterns appear tinted when this is done. One maker's sets glow a bright Kryptonite green when color is reduced to 0!
 

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Quote:
I know it's not for correcting red push and is for the greyscale, but when calibrating with Avia i lowered the color saturation to 0 and noticed when my screen is black and white the step blocks had a bit of a red tint to them.

You described a greyscale problem.


View some gray patterns on Avia or DVE, do they look gery to you? Adjust cuts/gains until it looks neutral gray to you. That's grayscale/color temperature, so that is on the mark.
 

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Discussion Starter · #4 ·
Thanks for the explanations guys! Yea i went into service menu last night while it was nice and dark and made the adjustment then. I didn't touch the RDRV tho, just the RCUT and noticed a much better gray when lowering it. If i lowered it any more than 10 it started taking on a slight bluish tint so i compromised. Should i also try messing with the RDRV as well? Put the RCUT back to default and see how just lowering the RDRV alone effects it? Or was just lowering the RCUT fine? The factory settings for the drives/cuts are


RDRV- 64

RCUT-120 ( i lowered this to 110)

BDRV-53

BCUT-64

GDRV-38

GCUT-80


I know for a fact too that at the factory they must just apply default settings to all the makes of my TV ( Old Sony Wega KV27FS100L) since reading some other forums i found out that many people with this same TV have the same DRV/CUT values.


I really love dabbling in the service menu tho and trying to get the best picture out of my TV. Been researching for a while now. Hell i even took my TV apart not too long ago and disconnected the eternal speakers since i only use my home theater and never use them. I thought it would clear up some discolaration issues i was having on the edges of my screen but it didn't
I was looking for the SVM wire while i was in there but couldn't find it!
 

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cut is the lower end of the red (like black level for red) and drive is like white level for red. So it depends where the greyscale problem is. Look at ramps and windows at different % from gray to white and see how things track and adjust accordingly.
 

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Discussion Starter · #6 ·
HMMM interesting. I think i'm getting the idea of it how you explained it. So i would want to also throw up a Full white pattern to check the RDRV? am i getting this right? and also a black for the RCUT as well as the grey steps? So i would still wnat to keep color to 0 while doing these tests? and i'm guessing boost up the black level while checking the CUT to see if it glows red? Thanks again for the help Chris. One more thing and i'll leave you alone!


When setting things to 0 like color and contrast. Are they REALLY at 0? or would i also want to turn down the Sub color and sub contrast in the service menu for TRUE 0?
 

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My Toshiba 24AF-43 Drive settings are

R=65 G=fixed B=63.


I lowered blue to 43 to counter some bluish glare I was getting but I think I have to lower the blue bias=141 because lowering the Drive causes a bluish background in very dark scenes(re: COPS night chases)


Just an example of the above interactions.


regards,
 
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