#1 thing to understand...
There is ZERO difference between calibrating an LCD TV, plasma, DLP projector, CRT, LCoS projector, or LCD projector... all of them should be calibrated to the SAME standard/specs... which is the HDTV spec as defined in the Rec709 document. You do not change ANYTHING for different types of display technology.
That single fact, all by itself, makes the "LCD" labeled setting in the AVR sound stupid... no matter what it does, it SOUNDS like a stupid idea since there should be nothing different about what you send any video display...
Because... there's as much difference in the appearance of images on LCD Model A and Model B and Model C as there is between a generic LCD and plasma or between LCD and a DLP projector. Furthermore, LCDs can have CCFL backlights (older models) or LED backlights with both have very different spectra which makes images look different. So which type of "LCD" is the AVR processing supposed to work well with?
Processing in AVRs is now a dumb, bad, & redundant AND a waste of time/money/resources that could be devoted to making the AVR better at audio. With 1 exception... if you can't bring yourself to update your vintage Blu-ray player to a new model costing $100-$500, processing in the AVR MIGHT be slightly better than what is in the old Blu-ray disc player. But in the last 2 years especially, Blu-ray players are MUCH better than they used to be (all of them lumped together) with few if any really needing external processing that can do a better job than the player's internal processing (but many older players with poor processing can't be set to avoid their internal processing anyway, so downstream processing STILL won't help since the poor internal processing already damages the image). There was a time period, say 2004-2007 or maybe 2008, where good video processing in an AVR was typically better than Blu-ray players in 1 way... for upconversion of DVD. But AVR designers aren't particularly good video engineers and I've never seen an AVR with REALLY useful internal video processing - mostly because external devices could not be set to NOT process the video before it gets to the AVR (or TV). For that reason, it is almost always best to disable processing in the AVR entirely if you are using a newer Blu-ray disc player, especially if it is a newer model, known to be accurate (Oppo models, some Panasonic models, most any PS3, plus others that have been tested and confirmed to be accurate). But in many AVRs, you can never completely disable the video processing even by selecting "Through" or "Pass Through" or "Off" or other setting that purports to turn off video processing... for whatever reason, AVRs still tend to mess with the video even when you THOUGHT you were just sending the video through without any processing. I'm seeing more and more surround processors and AVRs without internal video processing and that's promising.
Oh, almost forgot... on the "LCD" setting thing... even LCDs that have LED backlights... there are HUGE variations... some of them use "white" LEDs while others use quartets of LEDs (typically 2 greens, 1 red, and 1 blue) in groups behind the panel). Those two types of LED backlighting are VERY different and require very different processing to make the images look right. So no one setting in the AVR would be appropriate for all LCD TVs, even not for all models of one Brand for any one model year since the manufacturer may use white LEDs in edge-lit models and RGB LEDs in backlit matrix models with local dimming. Not only that, but where you set the backlight control changes the light spectra (distribution of different colors of light) a lot also, so when is that one "LCD" setting a good thing? When the white backlight is set to "3" or when the RGB backlight is set to "8"... it's just nonsense.
Edited by Doug Blackburn - 3/20/13 at 12:26pm