I have reviewed some older posts on this subject, but I have not yet found an answer to my problem. I am running a Sony D50Q with ABG ON and have some brightness instability at very low APLs. The chassis and tubes have less than 1K hours on them. The rasters are well-centered on the phosphors, and the ABG lines are not touching or overlapping the tube borders. I can't say for sure when this problem started or when I simply began noticing it, but it does affect all three tubes. I would like to avoid turning ABG off since this evidently requires recalibration and gamma changes, which I am not equipped to deal with yet. (The projector was ISF-calibrated years ago but I probably still have a good grayscale.) I had seen mention in a post that one should keep video content out of the ABG area but am unclear as to how to do that. The brightness instability seems to persist whether I have horizontal bars top and bottom on 2.35:1 source material or not (16:9 screen). Any suggestions on what to try next would be appreciated.

-RobH

Hi,

I have a G70 that I bought with over 10,000 hours on it. I re-tubed it and noticed some brightness instability with lower APL. I can't say if that the ABG was the cause of the instability but I usually have ABG off and don't have the problem with it off.

-Brian

Those flickers were anoying me also. I didnt really find a solution. Sometimes trying a different resolution and refresh rate works for me, but that is time consuming to re-register.

I turn off ABG without gamma adjustments. i just increase brightness and contrast to similar levels it was at with ABG on.

When turning off ABG and adusting brightness+contrast (no gamma), will the colorimetry be affected? I have had the grayscale ISF-calibrated and have no equipment of my own (yet!) to check color temps.

I have the privilege of living in a 300+ year old cottage. Nothing is straight and when putting up a shelf, I don’t use a spirit level, instead I use the “If it looks right, it is right” method.

I use this method for my G70 too.

If you turn off ABG you will certainly need to re-calibrate.

You can likely get a good enough job "eyeballing" it with a calibration DVD though.