Originally Posted by sam1289
With plasma's dont they will all suffer from raising black levels after a specific time of use?
The answer is no, but it's important to understand why. What all plasmas DO suffer from is declining brightness over time. As the phosphors are excited billions and billions of times, their ability to emit light when excited goes down. - - pretty sharply after a few hundred hours, and then more gradually for the life of the set.
Since one of the big marketing problems with plasma, relative to LCDs, is lower brightness to start with (More among mass market consumers than among the folks here, who are more likely to run their panels at lower brightness anyway) Panasonic set out to try to fix this.
Their solution was to have their sets automatically increase their drive voltages over time, so that brightness is maintained as the efficiency of the phosphors declines. The unfortunate side effect is that the increasing voltage also raises the set's black level. Again, for the mass market consumer, who watches TV with a lot of room light on, this is a non-issue, but for tweaks watching in a dark HT, it's a big deal.
This was compounded by the fact that Panny was pretty heavy-handed in how they applied this voltage correction on the '09 sets, so that black-level fans perceived a sudden jump after a few hundred hours.
Panny claims that they have fine-tuned the voltage correction on the '10 sets so that that change will happen much more gradually. It doesn't appear that people with '10 sets have run them enough yet to know how it is going to play out.