240Hz LCD TVs: What you need to knowMEMC vs. backlight scanningTo reduce blurring, most 120Hz LCD displays use a system called MEMC (motion estimation and motion compensation) to slip in a new frame between each of the original frames. The end result is one extra frame for every true frame.You'd think, then, that a 240Hz TV would just double this to achieve an even more blur-free picture. Alas, it's a little more complicated than that. The problem is that there are actually two different types of 240Hz, including one which doesn't bill itself as true 240Hz but rather as a "240Hz effect". Here's a breakdown of the two versions and which companies employ them. MEMC (motion estimation-motion compensation): Both Sony and Samsung's 240Hz sets use MEMC to basically double the 120Hz process described above. However, instead of getting one extra frame for each "true" frame, you actually get three extra frames. (See first take of the Sony KDL-46Z5500). Scanning backlight (240Hz effect): LG, Toshiba, and Vizio use what's called "scanning backlight" technology. Such TVs use MEMC once to get to 120Hz, but instead of doubling the interpolation, a backlight flashes on and off very quickly to achieve what Toshiba calls a "240Hz effect". LG, for its part, fails to make that distinction and uses the 240Hz term without qualification to describe its scanning backlight models. After having reviewed three 240Hz TVs that use MEMC and one, the Toshiba 47ZV650U, using the scanning backlight, Katzmaier reports that the MEMC version of 240Hz is slightly superior at reducing blur. But when he says that, he's referring to test patterns where models from Sony and Samsung scored slightly better than the Toshiba. The MEMC displays delivered between 900 and 1,000 lines of motion resolution, which matches the result of a typical plasma, while the Toshiba scored between 800 and 900. Again, watching everyday material, whether this is from a Blu-ray movie or HDTV content from your cable or satellite provider, we both maintain that the difference between having a 120Hz LCD TV and a 240Hz TV is virtually imperceptible. In other words, superiority is a very relative term in this instance. In terms of what kind of premium you'll pay for a 240Hz TV over a 120Hz model, you're currently looking at somewhere between US$200 and US$400 in the US, and we expect that by next year the gap will be even smaller. So, is it worth the premium? At this point, the answer is probably no. Objectively, in lab tests, you can't dispute the fact that 240Hz does seem to reduce motion blur. But in real-world terms it doesn't amount to much, if anything. As I always say, if you want the latest and greatest spec--and don't mind paying a little extra--go for it. The original story first appeared in CNET.comTags: 1080p, Motion, TV, Akihabara News, Philippines
|
- Talkback
-
maeglin80 says...
For some reason, I think 75Hz even makes a difference.
May 27, 2009 15:10
For some reason, I think 75Hz even makes a difference.
May 27, 2009 15:10
Zagatos says...
240Hz doesnt fix the problems that 120hz has, both of them still show halo effects and artifacts. So really there is no need to upgrade but obviously if buying a new lcd might as well get the new technology but if you already bought a lcd with 120hz there is really no difference with 240hz.
Aug 04, 2009 11:13
240Hz doesnt fix the problems that 120hz has, both of them still show halo effects and artifacts. So really there is no need to upgrade but obviously if buying a new lcd might as well get the new technology but if you already bought a lcd with 120hz there is really no difference with 240hz.
Aug 04, 2009 11:13
To post comments, you need to become a member. It's FREE.
