CurtPalme.com Home Theater Forum

[garyfritz]

I just did a grayscale touchup on my 8500 with Moome EXT-HD box. I've got the EXT-HD's gamma boost cranked all the way up -- the picture always looks too dark to me -- and it may be a bit high, but I prefer this to the "too dark" look. At this setting I can't see the 5% level in a "5% steps" pattern, due to the light spill, so I don't want to go much darker.

I'm a bit puzzled by some of the things I'm seeing. Check out the pix below. (HCFR file is also attached.) The color temp is pretty good, with a midrange hump but the delta-E is below about 6 through most of the range. The blue is already VERY defocused and I don't want to blur it any more.

Two things confuse me:

* The blue has a hump, which is not surprising, though with the amount of defocus I'm using I would think it would be tamed better than this. But what really surprises me is that the RED shows a hump too !??? The green looks perfect but the red has a hump almost like you'd see in a blue. Anybody ever see that before?

* The average gamma is 2.17, which is low but I think I'll stick with it for now. The odd thing is that the gamma for the green *rises*, and the blue/red *drop*, as the IREs go up. Is that typical? If not, how can I control it, or should I just leave it alone?

If you look at the luminance graph, all 3 colors are a bit high in the low IREs, and I don't mind that. In the higher IREs the average luminance (the yellow line) tracks the 2.2-gamma target almost exactly, but green runs low and R/B run high -- which is what the gamma chart indicates.

This higher-IRE gamma weirdness is so minor I should probably just ignore it. The color temps are fine. I'm just curious.

BTW this measurement was done with a Spyder2 that seems to be accurate, but...
Gary