[argyllcms] HDTV, IRE, and Rec709 - oh my.
- From: Greg Soravilla <greg_soravilla@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Thu, 10 Nov 2011 15:18:58 -0800 (PST)
Fellow enthusiasts - I could sure use your insight. Note this is in relation to using Argyll CMS to measure and adjust an HDTV. (This may be long, so a BIG thanks to anyone who responds!) Background: I just picked up an HDTV (Zenith Plasma) with 20 point IRE settings (+/- R,G,B for each) and "color management" (color & tint adjustments for R,G,B,C,M,Y) in addition to the standard fare (bright/cont/color/tint/white balance). While I found some suggested values for its LG cousin, I would like to leverage my colorimeter and PC to properly calibrate my particular set. So far I have read what I can find, absorbed what I can (a good day of reading), and now have various facts, assumptions, and questions floating about in my brain. Please, please, please correct anything that is wrong in any statements I make... I want to learn and wrap my head around all this!! My assumption/understanding of multi-point IRE controls is that they effectively map percentages of the incoming signal level (5%, 10%, etc) to an adjusted value for each channel (R,G,B). The purpose of which is to fix gray-scale tracking. My next few Qs are based on this (possibly incorrect) assumption, though the questions may still have some validity. Can and should IRE also be used to fix anomalies/mis-tracking in gamma? Does using the IRE controls pretty much dictate then that I have to pre-adjust for black and white points and that I cannot change the points later without redoing the IRE measurements and values? (I guess I am loosely asking how brightness/contrast play into the IRE settings.) Lastly, should the same IRE settings be applied to all my TV's inputs? If not, do any overlap (eg, all HDMI)? The IRE tracking from input to input brings up another important question - what should I use for source(s) when calibrating? If the IRE can be used from input to input, then is just my PC sufficient? Or do I need a DVD to pop in the PS3 and HD-DVD players for their respective inputs? If a DVD or video, is there anything suggested? Cheap/free requested if feasible. Not a requirement, though. I merely have far more time than money. ;-) Would I likely be correct in assuming the TV's color management controls would remap source gamut points (e.g. 'red') within the color space of the TV's gamut (e.g. target rec 709 red)? So red in the source actually lands on the correct place in the TV's gamut, instead of say 'orange-red'. I realize this may a be manufacturer specific question - I just don't know if it is. If so, any recommendations on out of gamut issues? (Suppose I can't actually hit a proper red or yellow) Is rec 709 using D65 and gamma 2.2? Would I use the LCD or CRT attachment from a colorimeter to measure a plasma TV? I assume CRT, but that could be wrong. Any tips for nailing skin tones are appreciated. If there are any good FAQs I have overlooked, please let me know. I'm sure there are Qs I had that I already forgot. That's enough for now! Thank you everyone for any/all input,Greg