120 Hz: Does It Matter?: One of the "hot" new features for LCD HDTV is a 120 Hz refresh rate. Okay, it's not all that new; I wrote about it in my CES coverage last January. But the products that include this feature are starting to show up on the shelves in even greater numbers, so I figure it's time to review the technology.
Most LCD panels refresh the image 60 times a second. This is fast enough to eliminate any image flicker for most viewers. The problem is that the liquid crystal molecules take time to react to the electrical charges in each cell, and you can get motion blurring between frames. By writing the image to the screen twice as often -- 120 times per second - it causes the liquid crystals to respond faster, and motion blur is decreased.
Many LCD TV manufacturers are also pulsing the backlight in sync with the image refresh rate. For those of you who are into the club scene (or who remember the disco days), you are familiar with the "freeze frame" effect of a strobe light. Flashing the light freezes the image, further reducing motion blur.
As a result, some LCD HDTVs with 120 Hz refresh rate create fast moving images that look nearly as sharp as a CRT, which still is the gold standard for smooth motion on the screen. Most viewers would have a difficult time telling the difference between the two.
(Read Original Article - Via hdtvprofessor.com .)
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