AVS Forum Special Member
Join Date: May 2008
Location: San Francisco - East Bay area
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Short answer is that, yes, you can set RGB gains and offsets higher or lower to adjust gamma... maybe, sorta, kinda. You might do better there, or not. Pro Studios doing mastering for movies are calibrated to 2.2 or 2.3 at the most, never higher... I find setting gamma to 2.25 looks best the vast majority of the time.
The reality is that many displays have gamma problems and lack the controls to make gamma uniform for all steps. There's no such thing as ONE gamma value for a display... you can average the gamma for many grayscale steps and get an average, but that can be VERY misleading because every step could have a HUGE gamma error and it just might happen that they average-out to looking OK. You really need calibration software that shows you whether each grayscale step is as bright (or dark) as it is supposed to be to achieve the same gamma target (say 2.25) for every grayscale step, not just as an average over the entire grayscale. TVs with 10-point grayscale adjustments make that fairly easy to achieve. TVs with just 2 grayscale adjustments (high/low, cut/gain, offset/bias) are much more problematic. Even if the TV has a gamma control, the settings can be pretty bad and not be close to the labeled gamma (meaning a Gamma setting of 2.2 may not measure 2.2 at all... or it may only be 2.2 at one point on the grayscale while other steps are too bright or too dim).
Finally, ColorFacts Pro is woefully out of date as calibration software. It is essentially worthless now. And the Spyder2 was NEVER a decent meter to use for calibration of anything... it would be somewhat OK for CRT or Plasma displays, but it is TERRIBLE for LCD displays (produces very inaccurate results) and can't really be used for projection systems as it can't take readings off the screen. And colorimeters drift as the filters age... after 3-5 years the filters change enough that the measurement results will very likely produce visible errors.
"Movies is magic..." Van Dyke Parks
THX -- ISF -- HAA