Originally Posted by Chad B
My calibration results on many 800u's disagree, not with the character you describe, but at least with the lack of "goodness".
I get, after proper white and black level calibration, a gamma of 2.05 at the low end to 2.3 in the upper middles. While this is not perfect, it is well above average. Better, in fact, than any plasma I can think of except the Pioneers.
Here is a calibration report of an 800u in THX mode.
Check the point gamma chart.
Samsung plasmas have 7 Gamma steps to choose from in the User Menu and the Service Menu will move the range of those 7 steps up and down. Furthermore, Samsung doesn't play games with lower gamma at low luminance and higher gamma at higher luminance levels. You can setup a Samsung panel to have a gamma as high as 2.7 if you want to... and it will measure very close to 2.7 at each grayscale step (perhaps not 10% though, crush may be creeping in at that point). I'm certainly not advocating DOING that, but it's quite possible. 2.3 or so seems to be a good setting for watching Blu-ray movies in a dark room. Side-by-side with an 800U in THX mode, with both panels calibrated, the Samsung will have more accurate color, lack the muddy/flat/dull appearance, and there won't be an obvious grayscale error at 80% that just about every 800U has. The A550 Samsung won't look quite as black as the 800U, but the A650 Samsung is a pretty close match for the black level of the 800U.
Last night I used a Lumagen Radiance XD to produce the same sort of gamma performance exhibited by the 800U in THX mode and found it upset the images in exactly the same way I object to in the 800U's THX mode. I used a Samsung plasma and a Toshiba LCD just to see what would happen with 2 different panels and 2 different technologies. I copied the results I've gotten from 800U calibrations.
There have been a lot of AVS Forum 800U owners who have the same complaint about THX mode... muddy and/or flat/dull. I've had calibration calls from at least 10 people wanting to know if I can remove the flat-dull look of the THX mode in their 800U and I had to be honest... no, there's nothing that can be done to eliminate it. Half of those calibrations were "lost" because of the inability to eliminate that gamma issue. You can futz with the cuts & gains to move the average gamma for the 800U up and down a little, but you can never remove the characteristic low gamma at low luminance, and high gamma at high luminance problem. The spread from 2.05 to 2.4 is HUGE - and to me it compomises the images far too much. When I see these panels I'm torn between using a 1.95-2.3 range or going a little higher (your 2.05-2.4 range for example). I'll take a Samsung A650 plasma any day over an 800U - with calibration, you can have nearly perfect primaries and secondaries, any gamma setting you want (without much variation from low to high luminance), and grayscale performance about on par with the 800U.