Originally posted by Michael.Chrisco
Thanks I liked looking at the graphs.
Question though, looking at your before graph couldn't you have just brought down the blue to get them all level? Instead of changing the gamma? Have you noticed the dithering and/or banding reduced with the lower gamma?
I have a 507 w/302 and wonder if before you did this is you saw purple lips on people (sometimes) and the NFL Vikings purple colors to be blue. It would seem that those would be symptoms of blue being to strong on mine.
I think I should post the "before" graphs for the luminance curve as well as the RGB values. The gamma value effects how grey values (and colors) get displayed at different "brightnesses" on a display. A 10IRE grey is really dark, near black, and a 90IRE is nearly white. What you want is a TV which makes these greys appear at the right "level" on a smooth curve. If you look at Gamma 4 it shows a REALLY odd curve - which seems to make the middle colors really "bright" to stand out - perfect for a showroom and what we're normally used to.
Colorfacts gives you an overal luminance value representing what curve best fits what your TV is outputting at various values of grey. 2.2 is a value for NTSC standard. 2.6 (I think) is HDTV (darker overall).
So what you want is a curve which looks like a curve - not really like what gamma 4 produces, which has a luminance value between 2.2 and 2.6. Choosing different gamma values gives you different curves and different values.
Once you have chosen your best curve you then adjust the red, blue and green mix to make sure each "grey" really consists of the right balance of the colors. As you can see from my "before" RGB - the blue was way too high - and red and green weren't that good either. I could have just left my Gamma on 4 and calibrated the colors - which would have produced a better picture anyway - but I also adjusted the gamma curve to give me a more accurate (although some would argue - and are - less attractive) picture.
In essence the two are slightly different things and if I would have liked to try getting the colors right on gamma 4 to see what it looked it - but I was only borrowing the colorfacts unit so ran out of time for that.
One of the problems with all *my* luminance histograms is that if you look at the lower IREs (the dark greys) the curve is below the line - this means that shadows will be overly dark whereas the other grey levels are spot on - meaning they will be presented correctly.
Oh, also you can't really just "turn down" blue independently as adjusting one color actually effects them all. Turning down blue would cause red to rise almost proportionally (and green to go up a little too). Turning green up reduces both red and blue. Its a balancing procedure which is why you really need some type of external unit to measure whats actually being put out and to see what adjusting one color is actually doing.
Hope that helps a little - and I'm sure people with more knowledge will correct me where I'm wrong.