Q: I am looking for a 240 Hz 47-inch LED/LCD TV. Not one of the retailers I visited is displaying anything 240 Hz. All the sets they have on the shelf are 120 Hz or less. If you want 240 Hz it has to be special ordered. What should I do: order one or settle for something on hand?
A: The "Hz" refers to Hertz, which is the refresh rate or scanning rate. It represents how many times the picture is drawn on the screen per second. A higher number does not mean a better picture, and I would not worry about this number when you are shopping for a TV. What is important is that the TV has good picture quality and can depict moving objects realistically (called motion rendition). You can judge that with your eyes.
You don't need faster scanning to get proper motion rendition. Many CRT, rear-projection and plasma TVs scan at 60 Hz and display moving objects without smearing or having an unnatural look. In fact, TV broadcasts are only 30 Hz (CBS, NBC) or 60 Hz (ABC, Fox, ESPN).
The interest in higher scan rates started when LCD TVs gained prominence. (LED is just a version of an LCD.) LCD pixels can't display motion in all conditions at 60 Hz. The solution was to increase the scanning rate from 60 times per second (60 Hz) to 120 Hz, then to 240 Hz. (With 3-D, even faster scan rates came along, but 3-D never really got a foothold in the marketplace.)
The problem with changing the scan rate and applying other motion-processing technology is that when you start modifying the signal or the way it is being displayed, it can create problems in the picture, such as fuzzy "mosquito noise" around moving objects, or motion that looks unnatural. The motion on your TV should look like it does in real life, or like you are watching someone though a window.
Sometimes I go to big-box stores and check out at some extremely expensive televisions selling for $3,500 to $8,000 and up. Usually they are playing an action movie such as "Avatar," "The Avengers" or "Iron Man." In many of the TVs I have seen, the actors' motion is unnatural and looks like it is CGI animation. In fact, in some cases I have seen CGI animated characters that move more realistically than humans. Sometimes you don't even have to watch carefully. It is plain to see, and if I watch it for a length of time, I start getting a headache because my brain is trying to compensate for what it knows is not right.
What bothers me most is that these televisions are being sold at premium prices and are very highly touted by the manufacturers and retailers. What is being displayed on the screen is such poor quality that the manufacturers should be ashamed. Fortunately, turning off the motion processing in the video menus usually (but not always) solves the problem.
I would rather have an inexpensive TV that works at 120Hz or even 60 Hz than a TV that turns actors into CGI versions of themselves.
Send questions to Don Lindich at email@example.com. Get recommendations and read past columns at soundadviceblog.com.