Black Level Shift while watching Bluray?

[Omega Supreme]

I have a Panasonic TC-P50 S2 plasma connected via HDMI to a Panasonic BD-65K. I have noticed on a couple of bluray's that I have had a black level shift while watching movies. I’m not sure if that is a good description so let me explain what's going on. The effect looks exactly like if you go into the TV menu and go to the "Black level" setting and switch it back and forth from "Light" to "Dark". It usually happens during darker scenes. I have only noticed it on 2 movies so far. It happened a couple of times while watching the latest Twilight movie. But this past weekend it happened continuously while watching The Social Network. 5 min. into the movie my wife (who usually doesn’t notice this stuff) asked what was going on. Like I said it is usually during darker scenes and everything would look fine then all of a sudden the picture would get brighter. A few seconds latter it would get darker and so on and so on. This would happen sporadicly, sometimes happening every 10-20 sec. to 15-20 min.'s. This only happens while watching bluray's so it makes me think it is the player. Anyone else notice this or have any advise on thing to try? Thanks for your help. BTW the Twilight movie was my wife’s selection

 

[j_garcia]

Does your set have automatic brightness / room light detection? Turn it off. I have a setting for movies that has this turned off, but I have a "normal" setting that we use during the day so it will self adjust so you can see better.

 

[jostenmeat]

From what I recall of the two Pana BDPs I've owned (no BD65 though) is that black level is simply either light or dark (light being preferred). The only auto setting that I can recall is perhaps the display brightness. Of course there are other "auto" things like idle time before shut off.

This is really weird. I am going to guess it's something to do with the TV settings, or a very strange TV characteristic. In my HT, most boundaries in the periphery are dark/black, and I don't recall shifting black levels the way you describe.

But this only happens with the BDP? How strange. It is connected through what receiver? (Not that I can help you, but I am curious.)

 

[j_garcia]

It is the TV, not the player, that will have auto brightness settings. Didn't look that set up, but if it is within a few years, it will have it. I can totally see it when mine is doing it, which is why I turn it off when it isn't light out.

 

[BMXTRIX]

From their manual:

http://www2.panasonic.com/consumer-electronics/support/VIERA-Flat-Panel-HDTVs/model.TC-P50S2

Page 26 of the manual calls it C.A.T.S.

Adjusts the brightness and gradation according to the ambient lighting condition. (Off/On)

Turn this OFF if it is on.

This just mimics what the above poster said, but gives you the details for your specific TV.

 

[sparky77]

Maybe there's a setting listed as a contrast enhancer, that's what it was on my Hanspree, I turned it off because it took a couple seconds for it to kick in, and kick out when the lighting level of the movie changed. After that carefully calibrating the settings using the Digital Video Essentials disk made up for not using the contrast enhancement.

 

[Hi Ho]

If your TV has C.A.T.S. then that is almost certainly what it is. I just discovered this myself! I had been noticing this phenomenon on occasion with my G25 particularly on dark scenes. It never really did it enough to bother me. After reading this thread I went and turned off C.A.T.S. and the problem has completely disapeared. 24 is a particularly good show to test for this problem as there are a lot of dark scenes and black boxes.

 

[Omega Supreme]

Im almost positive its not C.A.T.S. because I have all the processing stuff turned off on my tv. I may need to see if it has that setting in the bluray player ( I know it has the Blacklevel "Light" or "Dark" setting). I will double to check and see if I turned it on somehow. It makes me think it's the bluray player because I have never noticed it while whatching Sat. or over the air stuff. At first I thought it might have been the disk so I read some reviews of The Social Network and it seemed to get very good reviews on video quality.

Jostenmeat: I have the bluray player connected straight to the tv.

 

[sparky77]

While the tv is set for the bluray input try checking the settings again because they might be a per connection configuration.

 

[jostenmeat]

While the tv is set for the bluray input try checking the settings again because they might be a per connection configuration.

Good point, what sparky77 said.

Just for discussion's sake (as you should obviously double check on CATS everywhere), I suppose it's possible that even with CATS enabled everywhere, that it's possible you would only notice it with bluray. TV just can't get you the shadow detail that BD can, even if we are comparing movies on both. Now as for TV shows, sports, news, the avg brightness is just way higher than the avg brightness of movies in general. I know with my own OTA levels, they are just way higher in average brightness just as a signal, whatever is being shown. I don't do anything about it because I watch minimal TV, and when it's something like sports or TV, the chances that I'll have more ambient lighting is higher. Well my point is that when the material is brighter, you won't be seeing CATS doing its thing as much.