Sound Advice
By Don Lindich
Week 32, 2015
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. Does this matter, what should I do?
-D. McNay, New Hampshire
The “Hz” refers to 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 perfectly display moving objects, without smearing or an unnatural look. In fact, incoming TV broadcasts are only 30 Hz (CBS, NBC) or 60 Hz (ABC, FOX, ESPN.)
Changing to higher scan rates started when LCD TVs (and don’t forget, “LED” is just a version of an LCD TV) became more prominent. LCD pixels lag behind the picture and can’t turn off and on fast enough at 60 Hz to perfectly display motion in all conditions. The solution was to increase the scanning rate from 60 times per second (60 Hz) to 120 Hz, then to 240 Hz, etc. With 3D other advantages to faster scan rates came along as well, but 3D 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, you potentially open up a can of worms. It can create problems in the picture, like fuzzy “mosquito noise” around moving objects, or the motion itself looks unnatural.
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 like Avatar, The Avengers, or Iron Man.
The motion on your TV should look like it does in real life, or like you are watching someone though a window. In many of the TVs I have seen, the actors’ motion is unnatural and looks like it is CGI animation, not real humans. In fact, in some cases I have seen CGI animated characters that move more realistically. It is subtle, but it is there and if you watch carefully you will see it. In fact, you won’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 these televisions are being sold at premium prices and very highly touted by the manufacturers and retailers. What is being displayed on the screen is total garbage and I think the manufacturers should be ashamed for letting it get to market that way. 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. I will have more about this in an upcoming column, along with some TV recommendations.