CurtPalme.com Home Theater Forum

[perisoft]

So, since avisynth is still giving me fits, I decided to play around with colors a bit. I set up the D80 on an actual tripod (!) and decided to try calibrating the white point with the camera (I didn't try messing with gamma, though it's on the list).

I'd set the white point by eye, and found something interesting - it was WAY off according to the camera's onboard analysis, which shows a histogram for each channel - and it said that there was WAY too much blue, and the R/G balance wasn't so hot either. Knocking the blue back made everything look far too red to me, but I figured I'd let the camera do the talking and see where it got me.

For all of this, I had the white balance on the camera set to 6100k (it was either that or 6500, I think, and I wasn't sure what the standard is for HT - anyone know? I saw that NTSC is 6300 or such, but that seems pretty warm).

Anyway, as one might expect, this actually made the camera capture what was on the screen quite well, whereas before the colors looked completely wrong vs. what I saw on the screen.

So, without further ado, some results of the night's work. The camera's gamma seems to be off a bit - the low end is much more visible in real life than with the camera - but aside from that I'm pretty happy. All of this is SD, by the way.

[Nashou66]

you do need to do your greyscale, looks a bit greenish yellowish to me, use kals guide.

Athanasios

[AnalogRocks]

D65 or 6500K is the standard.

Interesting idea though.

[AnalogRocks]

D65 or 6500K is the standard.

Interesting idea though.

[johnsmith808]

For the life of me, I wouldn't be able to tell if the greyscale was off or not. That's one thing I've never attempted to tweak.

Maybe ignorance is bliss?

[perisoft]

[Brian Hampton]

I ran through Kal's Guide this Am.

(I just happened to have a few hours of "free time")

It was fun and useful. I'm very happy with the results.

-Brian

[perisoft]

So, I decided to mess with the colors some more this evening. It looks like the camera's a good way to set white point, but without MUCH better detailed gamma control, I don't see how I can do much for real gray tracking. The multipoint gamma app from the a-site works, but it's buggy as hell (pops an error box with each command but then executes it anyway) and nearly impossible to use precisely (eg, no grids on the gamma adjustment).

What's biting me in the ass is that I can get the low end gamma nice, but the *steps* are much bigger at low IRE than high IRE. The difference between 100IRE and 70IRE, visually, is maybe 10%, but the difference between 30IRE and 20IRE is more like 30%, even though 10IRE is still visible. You can see gradation all the way through; nothing is CRUSHED, per-se, but it's certainly not linear to the naked eye.

Pisses me off.

I tried ditching the weird custom ramps and playing with the Barco's cutoff/midlights settings WHILE playing with normal gamma adjustments on the PC - all by eye - and came up with this. It looks not bad colorwise, and is somewhat better on the squish-at-the-top and steep-at-the-bottom, but a comparison with the original I had going before suggests it's much 'less' at low IREs. They're not gone, just lower. But I don't know whether it's 'right' or not - no colorimeter and no $ makes perisoft a frustrated boy!

I finally got mt working with limitedsharpenfaster and threw a shot on there using LSF to show some sharpness difference. Obviously you can't see so much with the thing downscaled to ~850px wide, but you can still tell the difference. For some reason it's altering the colors a bit, too - gotta figure that out. I think it happens in the scaling step.

[AnalogRocks]

Loosing the yellow push.

[AnalogRocks]

Loosing the yellow push.

[Nashou66]

Much better, now i would not use what ever the LSF is, it messes up the colors. I like the look of it with out.

Athanasios

[AnalogRocks]

LSF Long Slow F...never mind

[AnalogRocks]

LSF Long Slow F...never mind

[Nashou66]