Westinghouse K840CK15 Restoration

[dtvmcdonald]

Originally Posted by etype2

That purple is very difficult to render properly, however my OLED reproduces the color well.

Its not the color that's the problem ... both my Sony Bravia and the CT-100 do that just fine.

The problem is that that color is one phase of Q, green is the other.
Thus, one gets bad color blur .

[old_tv_nut]

Originally Posted by dtvmcdonald

Its not the color that's the problem ... both my Sony Bravia and the CT-100 do that just fine.

The problem is that that color is one phase of Q, green is the other.
Thus, one gets bad color blur .

But if you sit far enough away, you are not supposed to see the Q blur, according to the original NTSC claims.

Actually, the minimum visual color acuity should be on a blue/yellow axis, but the NTSC choice of the I axis (orange/cyan) worked out well because skin tone is on the I axis and therefore you don't get any Q channel color distortion on the edges of faces. Making Q at 90 degrees to I then puts a mixture of blue and red (purple) variation in the Q channel, and the eye can see the loss of detail in that. It would be interesting to figure out how well things would have worked if NTSC had abandoned the 90 degree relationship of R-Y and B-Y, and put I and B-Y at 90 degrees instead. It would have other implications for the sensitivity of hue to burst phase errors, so not a straight-forward issue.