Originally Posted by SuperSam IR Issue Details
OK I spent last 5(!) hours researching the IR issue on my pn58a550.
YES IT DOES EXIST! Let me explain to what extent.
MAXDB properly caught me on writing that I was using white screen for IR checking which would not show IR. I was initially testing with the scrolling black gradient, but for some reason (user error) a paragraph describing it did not make it in the final version of my post.
I saw no IR issue on the scrolling gradient screen. I just checked it again - I am able to see NOTHING. During those tests the TV was running in CNET settings, with my slight adjustments.
However tonight I was able to successfully reproduce the IR people here talked about! I could only see it on completely black screen. Here is how.
My TV has been used for a total of approx 20-25 hours. I reset the TV to the factory default movie mode settings.
I played Transformers HD DVD full length (with black bars top/bottom) - NO IR on the black screen at all , may be because Transformers is not a very bright movie (fans, calm down, I am speaking in terms of colors/light).
Then I started playing around with the credits (white text on black background). I paused the HD DVD player at some point. As HD DVD users would now, in pause there is the scroller displayed on the screen, that scroller on Transformers is bluish. So I paused the movie and it displayed a good bold white line of closing credits plus the bluish scroller on the bottom. This was on the screen for 20 minutes.
Then I ran the scrolling gradient IR reduction thingie - no traces of IR. Then I switched the input to the cable box which was off so the TV displayed a completely black screen. I COULD SEE SOME FAINT TRACES of the closing credits line, and NO traces of the bluish HD DVD scroller. I then ran the scrolling gradient thing for 10 mins, and all the traces were COMPLETELY gone - my eyes actually started to hurt from all the looking at the screen from 10 inches distance tryng to spot the traces.
Then I switched back to the HD DVD input (with the same picture on it), left it for another 20 minutes, switched back to cable input, confirmed same faint IR, then turned the cable box on and played HDNET for 10 minutes, then switched to black screen again - NO IR traces this time too. This tells me regular dynamic picture removes slight IR just as well as the scrolling gradient.
I then repeated this test a few more times trying to find how long it takes (below 20 minutes) to cause IR, but since my eyes were tired, I am not sure I can provide reliable info on this. I am 90% sure I did not get it after 2-3 mins static, and it started appearing after 5-10 mins. The shorter the time was that it took for the IR to appear, the shorter it then took to get rid of IR with regular viewing or scolling gradient.
I then switched the TV to Dynamic mode (100 brightness, and cell light of max 10) and repeated this test. Yes Dynamic mode causes much faster IR.
Anyway, I just viewed cable box for the last 15 mins and then checked the black screen - all the IR results of my tests are completely gone.
I did not check how bad the IR would be if a static white on black is left on for a very long time (1 hour plus) - did not want to risk, as my TV is just too new.
One thing I noticed - if a screen is used to test the IR that is not completely black, the IR does not appear - be that dark gray screen or any other dark color.
I suspect the IR in this TV is just some kind of "memory effect" - can only be seen on 100% black screen with the cells switched off (or whatever that low luminance level is that produces the black color - i know the cells do not completely switch off). When there is any real color that is different from "default" black, the IR cannot be seen - to produce that dark (not black) color the cells are actually lit with real signal, more charge than the default/initial/standby black charge, and that charge resets the cell to the proper luminance that is of the exactly same level as the surrounding cells with no IR. So the IR cannot be seen. In other words, that "default"/standby black level charge effect is being changed by the IR, and the IR affected cells respond to it with more luminance and are not completely black, but then when a real color signal is sent to them, they light up with the right level of color. I am not making this clear I know, but hope someone understand my theory, which is all just my guess.
What do you guys think about this theory?
My conclusion - before this extensive test I have not even noticed the IR, viewing regular TV (with logos) and DVDs, and viewing the scrolling gradient anti-IR feature.
I have mostly been using the near Movie mode settings. Tried Dynamc just for a couple of DVDs and tonight for my test. This issue does not bother me at all, as does not affect my real life use of the TV - viewing TV/DVDs.
I will monitor the IR for a few weeks/months and will let you know if it becomes worse or better.