I decided to do some actual measurements so we can see exactly what is going on. Both consoles connected using HDMI to my Sony 70 XBR2. I used HCFR and an i1 pro to measure. (those with plasma or CRT displays, please pay attention to the bolded portion)

360 standard levels, black level set correctly for standard (measured contrast ratio 1861:1)
http://i178.photobucket.com/albums/w245/TheSerpentMage/360standardcalibratedgamma.jpg
360 expanded, black level at settings correct for standard (crushed blacks and high end color shift) (1456:1)
http://i178.photobucket.com/albums/w245/TheSerpentMage/360expandednotcalibratedgamma.jpg
360 expanded, black level set correctly for expanded (extreme high end color shift) (1702:1)
http://i178.photobucket.com/albums/w245/TheSerpentMage/360expandedcalibratedgamma.jpg

PS3 limited, black level set correctly for limited (1520:1)
http://i178.photobucket.com/albums/w245/TheSerpentMage/PS3limitedcalibrated.jpg
PS3 full RGB, black level set correctly for limited (crushed blacks) (1982:1)
http://i178.photobucket.com/albums/w245/TheSerpentMage/PS3fullrgbnotcalibrated.jpg
PS3 full RGB, black level set correctly for full RGB (high end color shift) (2895:1)
http://i178.photobucket.com/albums/w245/TheSerpentMage/PS3fullrgbcalibrated.jpg

The PS3 graphs have the contrast set conservatively while the 360 graphs have the contrast set high like many people do. If you like to keep your contrast set high, then pay attention to the 360 graphs because you will see that expanded/full RGB has a dramatic effect on gamma and color tempertaure, especially at the high end. The PS3 graphs would have looked very similar had contrast been set higher.

The expanded/full RGB graphs with crushed blacks are what most people are seeing if they don't use test patterns to set thier brightness control. As you can see it causes a darker gamma which is most pronounced at the low end. This will have the appearance of giving richer colors and a deeper picture. This comes at the expense of losing detail around black (severe black crush). This deeper and richer picture is why many people declare expanded/full RGB to look "better". However if you actually measure the TV with test patterns, it's very obviously an incorrect picture.

If you use expanded/full RGB with the correct black level setting, but do not lower your contrast, you will get a very blown out and discolored high end. It ranges anywhere from slightly blown out at the high end (see the PS3 graph) all the way to extremely discolored with a totally broken gamma at the high end (see the 360 chart).

Limited/standard with black levels set correctly makes for a very easy time setting your brightness and contrast control because it's not using the extreme ends of the video levels. You can get a reasonable picture very easily just by using your eyes to set the contrast and brightness controls. With expanded/full RGB you have to use test patterns to set the levels correctly or you will end up with a very incorrect image (though many might find it pleasing and actually prefer it to a "correct" image).

One thing to keep in mind is that if you are using a plasma or CRT based displays, there is a good chance that you may be badly overdriving the phospshurs using expanded/full RGB if your brightness is set correctly and you do not have you contrast setting farily low. Where a digital set like mine simply run out of a color (red in most cases) when overdriven, a phosphur based display will just try to display it by going brighter and brighter which may lead to a shorter phosphur life and possibly uneven phoshur wear (burn in). If I had a plasma or CRT and wanted to use expanded/full RGB I'd be very sure to use test patterns to set my contrast/brightness controls correctly and be very conservative on how high my contrast was set. Video games have a lot of static images and could be a potential threat for burn in.

If you use expanded/full RGB and calibrate it correctly, it will result in a picture that is near identical to limited/standard because in the end the picture can only be as good as your TV is capable of. Both black and white will be mapped to the same points. The only advantage that expanded/full RGB could give you is having more shades of color for RGB sources which may or may not actually be noticable.

.chc files attached for those interested.

Very interesting, thanks for that info.

I'll tell ya. After reading, I changed my setting back to normal to save my plasma.

Thanks much!

I'll tell ya. After reading, I changed my setting back to normal to save my plasma.

Thanks much!

Why would you have it on anything else? Old plasma with crappy blacks?

9uk.

Cause I wasn't paying attention...

Oh come on. When will this board finally grow up and quit with the plasma burn-in FUD? Damn!

I think it's interesting that there is indeed a slight difference in the picture setups between the PS3 and 360, which confirms what a lot of reviewers have hinted at. I guess that people using a switch to run the PS3 and 360 into the same TV input will have to find a compromise for their settings.

Also, for those of you now looking for a "contrast" setting on your set, please note that a lot of manufacturers, like Sony, use the term "Picture" for their contrast slider.

Oh come on. When will this board finally grow up and quit with the plasma burn-in FUD? Damn!

Well, it's not all "FUD". If you use reasonable settings and a variety of viewing material, I'm sure the chances are minimal of burn in. But if you turn your contrast control up to it's maximum and leave in on a channel with one of those tickers running across the bottom for a few weeks straight, I'm sure there would atleast some effect on the screen. Well if you run using expanded/full RGB with your contrast cranked, it will overdrive the phsophurs to some extent. This might not be a problem for gamers that play a variety of different games, but those that play large amounts (hundreds of hours a month) of something like GTA4 or CoD4 online might end up seeing the HUD cause issues after a few months. Mostly it was just a common sense warning, ie don't go out of your way to cause problems on your plasma/CRT.

From my measurements above:

Contrast set high
Xbox 360 light output of 100% white using standard = 57ftl
Xbox 360 light output of 100% white using expanded with black crush = 64ftl (12% increase in light output)
Xbox 360 light output of 100% white using expanded with black level set correctly = 64.4ftl (13% increase in light output)

Contrast set conservatively
PS3 light output of 100% white using limited = 43.4ftl
PS3 light output of 100% white using full RGB with black crush = 52.3ftl (20.5% increase in light output)
PS3 light output of 100% white using full RGB with black level set correctly = 58.9ftl (35.7% increase in light output)

Using expanded results sizable increase in light output over what you would normally get using the same exact contrast settings with standard (this is part of why people think expanded looks "better"). Using expanded is like taking your picture/contrast control and cranking it up. The 360 footlight results would have been much higher, but expanded actually maxed out red, green and blue on my set which limited the light output. A plasma/CRT would just have attempted to send the level of increase that the PS3 results show.

i dont understand how you can get accurate readouts when these settings only apply to 480p sources. i flipped these settings back and forth and they look exactly the same. becasue their supposed to with hd content. this needs more explanation.

i dont understand how you can get accurate readouts when these settings only apply to 480p sources. i flipped these settings back and forth and they look exactly the same. becasue their supposed to with hd content. this needs more explanation.

That only applies to the 360 when using component cables. When using HDMI it affects all resolutions.

So if I am just using the same calibration settings as my Blu-ray Disc Player, I should use the standard settings on a Xbox 360, right?