originally posted by drapp1952:
Someone who knows otherwise please correct me or elaborate about the following. An enthusiast could use a sensor and software (see the calibration forum) to measure the affected fields' x,y,Y data, through the gamma 3D menu adjust RGB, one by one field by field so that each was as close as possible to D65 x=.313 and y=.329 and a reference Y (luminance). You would simply measure each affected fields' x,y,Y through 11 gray steps and adjust each for best match with an adjacent and reference field. Let's say 15 fields have some kind of color uniformity problem. You'd have 11 x 15 RGB adjustments for ideal RGB gamma tracking for each field. An ISF calibrator might be consulted, but it might be like asking him to do 165 calibrations, and more if there were interactions between adjacent fields requiring adjacent touchup adjustments. Maybe a calibrator would have speedier means of doing all this, but you'd better ask ahead of time.
In my experience, shading problems rarely occur in one place on the screen throughout all the IRE levels. Shading non-uniformity can vary greatly across different level gray fields - to the point of being inverse at certain levels. It is also my experience that if a given "level" has a shading issue, it will require adjustment of arroximately one third of the 273 adjustable points on that "level". You are correct that the points adjacent in space (above, below, and to the sides) as well as adjacent in "level" (darker and lighter) are affected and usually need to be adjusted also.
In theory you are correct. Your method of placing a sensor in all of these problem spots can be done, but it will take a very dedicated owner enthusiast to devote this amount of time to a projector. Before one even begins to adjust anything, one must enter the original data for 7,371 points. (9 levels x 273 places x RGB). As someone who has done this by eye, and done simple grayscale calibrations using a sensor, I can't imagine the amount of work involved in using a single point sensor to do this.
I hope Sony gets this right on the Pearl, but their track record with LCDs is inexcusably poor. I have seen well over a dozen Sony LCDs beginning with the 10HT, through the HS51 and they all have had some degree of very obvious shading problems. On all of the units I have seen, and from the reports on this forum, all the units seem to have the shading problems in the same place on the screen - indicating faulty equipment or procedures at the Sony factory. I have seen five Yamaha LCDs - none of which had any problems. If William can do this right at his place, and Yamaha can get it right at the factory, there is no good reason for Sony to consistently turn out unit after unit with problems in the same places.
I'm not a Sony basher. I have owned the 10HT, and the HS51. I hope to buy a resonably well shaded Pearl. But from a black and white film lover, Sony deserves some bashing on this issue.