Originally Posted by cp22
Zmad, any suggestions on settings if gamma is raised to +2. -2 is a little to dark for my liking.
cp22, well from the proper calibration standpoint I couldn't recommend anything higher than -2. Here is why:
The reference calibration is done to gamma measurement of 2.2 (higher means darker). This is the optimal gamma for in-home TV's. Movie theaters are calibrated to darker gamma like 2.4 or so, which would be too dark for in home viewing unless you have a completely dark home theater yourself
For nighttime viewing, one would want to calibrate maybe slightly darker than daytime settings (say 2.3 gamma).
Now where is Sharp's 640U gamma in all this? Game mode allows reaching only a gamma of 2.0 (remember lower number means actually brighter grayscale and more washed out picture), and that's with gamma slider set on -2. So if you are using the game mode, you are already brighter than the reference. 2.0 is still acceptable though, especially in brighter conditions, but changing the gamma slider to anything else than -2 starts moving you into area of too light grayscale and too low gamma (the +2 gamma setting on 640U measures maybe only 1.8 or even 1.6 gamma, which is way off from where you'd wonna be).
Movie mode does allow reaching the reference 2.2 gamma (or just about 2.2), again with the gamma slider set on -2. So overall, this TV has too light gamma by default and requires the -2 gamma slider adjustment just to get close to where it should be.
Now, without using a meter and actually measuring your gamma, I can't say if you may or may not need to adjust the gamma setting, although this is something I would expect to be consistent enough between sets that the same setting of -2 should apply. So at this point it becomes a matter of your preference, but try not to get too light and washed out, which causes loss of depth in your picture...
I'd probably recommend to look into your dynamic range instead: contrast and brightness settings. "Contrast" will adjust the brightness of your whites and determine how white will your brightest white be (too high makes you loose white details though: say in a scene with a person wearing a white shirt you may not see the pleats and wrinkles on the shirt but just a bright white surface, which means loss of white detail). "Brightness" setting on the other hand adjusts your blacks and determines how dark your darkest black will be. So opposite of contrast setting: if you go too low with brightness, in a scene with a guy wearing a black shirt you may not see the pleats and wrinkles but just a black surface, i.e. loss of dark detail.
Also, you might bump the backlight setting even higher and get more light output, which might be what you are trying to get? The +8 setting I use puts out 40 fL (which is good for daytime and not too bright for nighttime either). One can go even higher (say +12 or even +14) and get closer to 50 fL light output. I'd only worry that that much light will increase some clouding and enhance the screen uniformity issues of this TV...
Anyway, hope this gives you a few things to play with and see what works for you...