Originally Posted by Tigerriot
Flashing lighting either exists, or it doesn't. There isn't an in-between. Here is a pic for demonstration. The four corners of the dark image are lit up brighter than the rest of the screen.
During a dark scene in a movie, the flashlighting will be visible if the TV has a problem with it. Clouding is simply flashlighting but in areas other than the corners. It's a brighter area on the screen.
In my experience and knowledge of current TV's, the Sony models seem to have more issues with this than Samsung. Samsung seems to have made great strides in this area with this year's models. My evidence for this is mainly based on CNET's reviews, which mention all the current Sony models has having flashlighting issues, while they mention the Samsung models haven't almost no issues with it. I also bought a 46" Samsung B530 earlier this year, and it had very good uniformity, but I ended up returning it anyway because I wasn't sure about what I wanted at the time.
Flashlighting exists if the viewing conditions allow for its observation. Most folks, if they so desire, can minimize or eliminate them with tuning such as using Will's setup for dark room viewing. I have a well lighted viewing room so I haven't messed with the backlight level, contrast, and brightness to try to affect the one corner I have a few times seen a flashlight. OTOH, in real-world viewing, one seldom stares at a black screen image like you posted for an extended period of time. Unless you are on PAUSE, most video is fairly fast moving and unless you are staring at a flashlight affected corner the moment that corner gets dark enough to show it, you will likely miss it. That is not to say that some folks haven't received HDTVs that are defective and have very pronounced flashlighting even in normal viewing conditions.
As to clouding, the clouding I see is source dependent. For example, I can watch the Dark Knight from start to finish without ever seeing a cloud despite most of movie being dark, night scenes. OTOH, watching SyFy HD's presentation of old X-Files episodes produces obnoxious clouding in any night scenes. Same thing with some poorly re-mastered HD movies on Starz. So, the clouding I cited isn't related to the flashlighting issue.
As to which HDTV manufacturer has more problems with flashlighting, I believe it is model or series dependent. For example, all of the Samsung LED LCD HDTVs are reported to have flashlighting problems due to Samsung's poor execution of LED edge lighting or the limitations of that technology. Back in spring when I was following the B750 thread closely, there were several purchasers that complained of flashlighting and returned or exchanged their sets. I don't think the percentage of complainers in this thread is any higher than what I saw in the B750 thread.
BTW, studying your BD intro photo I only see flashlights in 3 corners, not 4.