Originally Posted by Some dillweed
Yeah, sorry for my ignorance. I actually just figured this out earlier tonight after realizing that the way I've been calibrating for PC has basically been wrong this entire time, and came back to edit my post to say "Never mind, I'm an idiot." edit:
Okay... wait... I've been using the 4:4:4 EDID override on my Nvidia card for a while now, and at the default settings on brightness, contrast, etc., the High black level setting shows the right levels. Changing to Low crushes all shadowed areas into black and blows out brighter areas. Also, I just checked all three modes (Standard, Wide, PC) with the same main settings (backlight, brightness, contrast, color, color temp) and everything else at default besides sharpness, which is different on the PC mode. Unadjusted, uncalibrated, and unprofiled, the 25% stepped saturations all look very similar but with slight differences in the amount of colour and luminance.
They all show "Screen (RGB-PC)" under the settings. So, how are you supposed to know whether your TV is getting a YCbCr444 signal or an RGB signal? What difference does it make to calibration, and how does calibrating a 4:4:4 PC signal differ from an RGB PC signal?
As I understand it, I'm not actually supposed to touch the grayscale or CMS controls and am just supposed to use the colorimeter and software like ArgyllCMS to calibrate the video card gamma curves and create a profile. I am
confused now as to which signal is right, which mode is right, which gamut is right, etc.
Its ok. We all start out as "idiots" lol.
As for 4:4:4, for the 3 rgb subpixels inside of the main pixels on your TV, if you have anything lower than 4:4:4 (4 bits per component horizontal, 4 bits per component vertical, 4 bits configuration (square-shape)) like 4:2:2 or 4:2:0, it is called chroma subsampling (color informational is being taken away) and is WAY more apparent at native resolution. The red component is sacrificed more and more as you have a lower chroma. This is why magenta and red small text will be blurry with a PC that offers 4:4:4 (everything else will be blurry too but not as noticeable). This is why you want no subsampling (4:4:4) using a PC (or game console).
You can tell if your using an RGB signal or YCbCr signal by the Black Level setting you have to use to get true black. Again YCbCr (compressed range 16-235) for LOW and RGB (full range 0-255)for HIGH. Currently, anywhere you use a device that uses a physical media for transferring video (set-top box, DVD, Bluray) will most likely be using YCbCr as saving bandwidth is key for them. Might change
Once we have the ability to send uncompressed color over long lengths.
You CAN do the 10 or 20-point IRE without a colorimeter, but you need a 10/20-point grayscale test image to go by. I used my EYES and an Xbox 360 Indie game called TV calibration (240ms points) that has a gradient grayscale image you can use (either in block-gradient or smooth gradient) to see which IRE steps have color tint the gray value they represent. You use OUTER pattern on your TV if you do it with a test image and INNER if you are using a colorimeter. Colorimeter will the most accurate, but if you don't want to pay for that service and want close-to-perfect grayscale that hard to detect much error, use the test pattern method.
As for gamut, mode, signal, etc, just put gamut to Wide and leave it if your not sure. All others hold certain colors back to match the type of media they represent. With Wide, you get am all-around saturation for anything, but may not be perfect. PC mode (with expert picture mode) for RGB signals and no PC input label/mode (with expert picture mode) for YCbCr.
Color format/signal, PC mode, and Black Level all go hand in hand. If you select a wrong one, this is where calibration looks off at first.
One more thing, PC mode is also the "advanced" game mode. Game Mode on TV's only turns off enhancments like dynamic contrast or noise reduction for reducing video delay, but doesn't change the method of scaling or color processing that also contributes to video delay. PC mode is better for gaming, but only if you have a progressive resolution (60hz or 50hz depending on region. Not 24hz) and use a VGA or HDMI cable. So older consoles that do not have these connections and TV's that do not have the PC input label (for HDMI) are not going to be easy to play with when using a fixed-pixel display.
This is confusing stuff and you must take each piece of information with a grain of salt to realize what it does for everyday viewing.
(Sorry for errors. Typed this on my smartphone).Edited by MDA400 - 7/18/13 at 10:58pm