Quote:
Originally Posted by alluringreality 
In the portion you quoted I was just saying that xy values from measurements on the CIE diagram are generally not expected to vary much, regardless of the pattern chosen. The pattern 'A5 - Dynamic Brightness' has more to do with gamma, Y measurements, or light output (rather than xy measurements). One of the reasons for including the Dynamic Brightness pattern was simply to look at how some display controls function, and it can also be used to observe that various displays react differently to changes in average brightness.
The "Black Level Bars + Steps + Varying Gray" pattern on the Avia II DVD is a similar idea. That pattern also has some constant video level bars on the screen and average brightness increases as the video plays. Either the Dynamic Brightness pattern or the Avia video hint at the issue of measuring typical windows while trying to "calibrate" gamma. As these patterns indicate, various displays simply do not perform similarly regarding light output as average brightness changes. When someone measures Y with typical windows they are measuring a changing average brightness, along with measuring different video levels. With the APL measurement patterns they are only measuring different video levels, while average brightness remains constant for the series. Measuring gamma with windows is sort of similar to trying to measure the bars from one of the patterns mentioned as the video plays (See Example). Measuring the APL series is similar to pausing one of the patterns mentioned (so average brightness remains constant) and looking at the bars.
Example: Typically on consumer plasma the light output (Y measure) of the bars will change as average brightness adjusts, and usually with fixed backlight LCD the light output (Y measure) for individual video levels remains constant as average brightness changes - which is basically what you stated.
In the portion you quoted I was just saying that xy values from measurements on the CIE diagram are generally not expected to vary much, regardless of the pattern chosen. The pattern 'A5 - Dynamic Brightness' has more to do with gamma, Y measurements, or light output (rather than xy measurements). One of the reasons for including the Dynamic Brightness pattern was simply to look at how some display controls function, and it can also be used to observe that various displays react differently to changes in average brightness.
The "Black Level Bars + Steps + Varying Gray" pattern on the Avia II DVD is a similar idea. That pattern also has some constant video level bars on the screen and average brightness increases as the video plays. Either the Dynamic Brightness pattern or the Avia video hint at the issue of measuring typical windows while trying to "calibrate" gamma. As these patterns indicate, various displays simply do not perform similarly regarding light output as average brightness changes. When someone measures Y with typical windows they are measuring a changing average brightness, along with measuring different video levels. With the APL measurement patterns they are only measuring different video levels, while average brightness remains constant for the series. Measuring gamma with windows is sort of similar to trying to measure the bars from one of the patterns mentioned as the video plays (See Example). Measuring the APL series is similar to pausing one of the patterns mentioned (so average brightness remains constant) and looking at the bars.
Example: Typically on consumer plasma the light output (Y measure) of the bars will change as average brightness adjusts, and usually with fixed backlight LCD the light output (Y measure) for individual video levels remains constant as average brightness changes - which is basically what you stated.
Thanks for the reply. Many of us new to plasma notice that the black letterbox bars change as the scene varies, and there is a lot of complaining about this in the threads of these Samsung. Seems like this is perhaps more prominent in the current models than previously, and maybe I'm not correct in saying it is us new to plasma.
Some have tried to tell Samsung or show Samsung techs this but have difficulty showing it at times in the daytime. I found that the A5 pattern did this fluctuating and thought maybe this was a good way to demonstrate this flaw.
If in fact it IS a flaw. Maybe it's just what plasmas do. I get the feeling that's the case from what you say.
