Flat Panel Break In
First, let me explain the overall importance of breaking in flat panels before calibration. Most manufacturers run their TVs at the factory for some period of time before shipping them out, but users have no way of knowing how long that was doneperhaps the company wants to get the product out the door quickly, so it shortens the factory break-in period. Since all light sourcesphosphors, fluorescent lights, LEDschange over time in one way or another, and you don't know how much the TV you just bought was broken in at the factory, it's a good general rule to run it for around 100 hours just to be sure the light source has stabilized.
Plasma phosphors generally exhibit more initial instability than LED and CCFL (cold-cathode fluorescent) light sources in LCD TVs. Also, plasma displays are more prone to image retention at the beginning of their life, making break-in more important for plasma than LCD TVs. This is why we break in plasma TVs but not LCD TVs before calibrating them in the review process.
That being said, it's still a good idea to break in an LCD TV before calibration in the home. The intensity of LEDs changes over time, especially with edgelit models because there are fewer LEDs being driven harder than in backlit sets. And CCFL (cold-cathode fluorescent) backlights change in both intensity and color over time, so breaking in CCFL LCDs is more important than with LEDs. But I would run any flat panel for about 100 hours before calibrating it for home use.
When breaking in a flat panel, use full-screen (16:9) moving images or a solid gray field. Don't leave the TV tuned to a 4:3 channel or watch mostly 2.35:1 movies, which leave black bars on the sides or top and bottom of the screen. The entire screen should be stimulated equally during the break-in period.
If you have an A/V question, please send it to firstname.lastname@example.org.