Brightness, Contrast, Hue, etc.

[LavaJockey]

When I play a VHS tape directly to the TV it doesn't look the same as when I
play back the captured AVI file to the TV (via TV OUT). I can adjust the
brightness, contrast, hue, and saturation settings for my capture card and
my playback program, and I can get it to look right for some particular
scene. But when I switch to another scene, or try to capture another tape,
they are not necessarily the same. I think I'm doing it wrong.

So, is there a "correct" way to set the Brightness, Contrast, Hue, and
saturation? Maybe a test image and a set of procedures for adjusting the
levels? My wish is that I can set these things once, and then my captures
for any scene, or any tape, will look the same as the original tape. Is
that possible?

[stanwebber]

i imagine the gamma settings for your desktop will impact the tv-out in some way or another. my system's tv-out has its own set of color correction settings as well, and both impact display output

[mikk]

lol
so u're trying to get 2 totally different devices to match!

u'll probably have a hard time... even different vcrs from the same manufacturer don't have matching colors. they all seem to have their own ideas about what looks good. don't forget that devices have limitations too. a cheap vcr or video card won't be as good as an expensive vcr or video card (generally speaking).

one thing that could be having a big effect is the colour scale differences. video ranges from 8-235 and pc ranges from 0-255. that means that black on a tv is 8, and white is 235. on a pc, black is 0 and white is 255. if your tv is set up properly, anything below 8 should be black and anything above 235 should be white.

your video card might be putting pc scale onto the tv. that would make the dark bits darker and the light bits lighter. so on a properly calibrated tv, the dark parts would be black and the light parts white. detail would be lost in the very dark and very light areas.

my geforce2 shows dvd on the pc scale, while my old i740 uses the tv scale. it's annoying because many (crummier) dvds are authored on the pc scale, so the geforce2 just dumps anything below 8 and above 235. it then scales the colours so that 8 becomes 0 and 235 becomes 255. so detail that was in the dark and light bits is lost. i haven't worked out how to fix it yet.