[Wonderment]

Just did the Avia disc. Flesh tones are green.


How to remedy? (Granted, I'm color blind, so it is harder to do color evaluations.)



Ack!

 

[ChrisWiggles]

Find someone who's not colorblind to help you with this...

 

[PJINMN]

Do you have your input set to component? Colors will be off if the projector thinks its VGA.

 

[Shift]

Wear sunglasses

 

[T-Bone]

... or be green with envy... the 2 greens will cancel, and a fine picture will result! No kidding, I read it on the internet

 

[bteagarden]

I had a similar, but not exactly the same problem.

Before calibrating my X1, I did my TV which is in the same room. I did the beginner's walkthrough, in which they have you do only the blue bar test. TV looked great.


Then I did the same thing to the projector. Did the blue bar test, and got it pretty close to right. The color encoder check that followed showed that I was dead-on for blue and green, and 5% high on red. So I popped in Spirited Away, and was really disappointed. Everything was tinted a little green, but skies and anything else that should have been blue was horribly green. Double-checked my calibration later, but the blue bar test still looked good.


Since the TV is right next to my "screen" (white sheet), I turned it on and started comparing the images and fiddling with the projector settings. I also did a lot of swapping between Avia, Spirited Away, and a few other dvd's. What I came up with was this (at least for the X1; don't know what projector you have):


Start with the "Video" preset (turns off the white segment of the color wheel)

Set Color temperature to "Warm" which is supposedly closest to NTSC

Do the black and white level calibrations

Do the blue bar calibration, but only do saturation, ignoring tint

Switch to the green bar calibration that's in the advanced menu. Adjust your tint here, trying to get the bottoms of the 4 bars on the left to be equal using the green filter. I ended up having to set tint to 63 (out of 100; 50 is the default). If I used only the blue bar test like they do in the walkthrough, It would have put the tint down to 40 or so, which caused the green.


I wonder if there isn't something incompatible between DLP (or at least my particular X1) and the blue bar test. When my X1 is set right and the colors match those on my TV (which was calibrated using the same Avia disc, using only the blue bar test) the blue bar test on the X1 image shows the tint to be way off.

 

[JeffStickney]

Were you using component input, and was the red cable plugged in all the way. I am asking because I saw the same thing when watching a DVD- it was driving me nuts- then I discovered the red cable was not pushed in far enough. D'oh!

 

[Josh Z]

Quote:

Originally posted by bteagarden I wonder if there isn't something incompatible between DLP (or at least my particular X1) and the blue bar test.

A friend and I were discussing this recently, and this is what he said:


"One disturbing thing that I learned recently, however, is that the old,

familiar method of calibrating your NTSC decoder by looking at color

bars patterns through a blue filter isn't necessarily valid on non-CRT

displays. The blue filter method assumes that the blue filter will

show exactly the level of the blue signal output from the NTSC decoder.

The modern standard NTSC color space (SMPTE-C) assumes red, green, and blue primaries that match standard CRT phosphors. The primaries on our projector are different. In particular, if you use color correction

settings to adjust the color of the primaries (to hopefully better

match the standard primaries), that actually can cause some mixing of

the projector's actual primaries when displaying standard primaries.

What this means is that green or red signals coming out of the NTSC

decoder might actually include a little bit of the projector's blue in

order to get them closer to the standard green or red, but this little

bit of blue would be seem by you through the blue filter, thus messing

up this technique of calibrating the NTSC decoder using the blue

filter. This issue is described by Guy Kuo here (although his

explanation isn't entirely consistent with mine):

http://www.avsforum.com/avs-vb/showt...96#post4161596


As he describes, if your NTSC decoder is outside your display (like in

your scaler) and is connected with an analog RGB connection, then you

can work around this by just disconnecting the red and the green

signals while doing to the NTSC calibration. Some displays support

doing this internally.


So I'm not entirely sure what this means I should do for NTSC

calibration. Should I put all of the color correction settings to zero

before calibration? Or some other value? Guy Kuo recommends putting

the primaries where they turn a corner on the CIE chart, but he doesn't

suggest where to put the secondaries. I'm feeling a bit in the dark

here.


Regarding those color correction settings, though, at least I think I

have some idea that goal is to have the respective colors read as close

as possible to certain xy coordinates on the CIE chart."