Refresh rate, motion blur a nonissue on modern LCDs?
DisplayMate's testing lab during the LCD evaluation.
(Credit: DisplayMate)I've been testing LCD monitors consistently for the past two years. In that time, I've run various tests designed to evaluate a monitor's response time. I've used games, movies, and the occasional scientific test to confirm if a manufacturer's claimed response time is accurate.
To be perfectly honest, I have a very difficult time seeing motion blur in movies and games. In fact, I'm not sure I've seen it any repeatable evidence of it on a modern monitor during a game or movie.
So it should go without saying that DisplayMate's recent findings on LCD response times come as no big shock to me. The findings come via an article by DisplayMate founder Raymond Soneira.
Here are Soneira's major conclusions based on tests conducted by DisplayMate on LCDs from major manufacturers.
1. A manufacturer's claimed response time specifications are not a scientifically accurate or a meaningful indicator of picture blur.
The motion blur DisplayMate measured on the HDTVs tested was more than 40 milliseconds. According to the article, this is more than a factor of 10 greater than the manufacturer's published specifications.
2. LCD manufacturers have made a big deal about refresh rates in the last couple of years with the jump from 60Hz to 120Hz and now 240Hz. CNET's own David Katzmaier suspected that benefits with the jump to 240Hz were dubious already, but here's more evidence to back it up.
According to the article, regardless of whether the HDTV in question used a 60Hz or 120Hz refresh rate, there was no visually detectable difference in motion blur performance. The same held true for features that purportedly lessened the motion blur effect, like strobed LED backlighting and motion enhancement processing.
3. While DisplayMate found considerable motion blur while using in-house developed test patterns, motion blur was not visually detectable in real live video content during the extensive side-by-side testing.
Soneira concludes that "with only a handful of minor exceptions, whenever blur was seen in live video we always found it to be in the source content or a temporary visual illusion that disappeared when the segments in question were reviewed. This is undoubtedly due to the way the brain processes and extracts essential information from dynamic and complex moving images. It's very easy to think that you see blur when you're looking at lots of fast action on a single TV."
4. As a result of these findings, Soneira recommends the following. "If you stick with the mid- to top-tier models from the reputable brands, you should ignore response time specifications, not worry about LCD motion blur, and don't spend extra for 120Hz or higher refresh rates, strobed LED backlighting, or advanced motion blur processing."
Soneira adds, "These results and conclusions will surprise many technically-savvy consumers and videophiles because there has been so much talk about response time and motion blur. Like plasma "burn-in," some of this is just old information or echoes from all of the LCD marketing brouhaha. It's also very easy to think that you see blur when you're looking at lots of fast action on a single TV."
Keep these findings in mind when shopping for your next LCD monitor or HDTV; however, always remember that regardless of what any article says, your eyes should be the main dictator of what you buy.
Even though I personally can't stand the effect 120Hz refresh rates have on movies, there are some who prefer it over 60Hz. So if you're buying a TV so that your movies have that "filmed on video" look to them (blech!), then 120Hz will still be a viable option for you. Also, note that games were not tested during the evaluation so your mileage may vary there.
The full article is available here and as are related articles here. All are very much worth reading if you're interested in LCD displays and the technology behind them.
Eric Franklin refused to write a bio, saying, "Why are you bothering me about this bio business again? If I wanted people to know more about me, I'd send them to the Inside CNET Labs Podcast" (shameless plug). E-mail Eric. 
Of course, LED is even lower in power consumption, but they are also a lot more expensive right now and they have their own first gen issues. OLED will be even better than simple LCD with LED backlight, but it will be awhile.
People who can't tell the difference between LCD and Plasma are people who watch reality shows on their Vizios and watch movies in 120 Hz that make film look like video. Faster Hz is good for Sports, News, taped sitcoms and games, not film.
The first 100 hours (first month or so of viewing) of a new Plasma TV set is important for users to watch full screen (non-letterbox, non-4:3) with brightness not set at high. This moves the phosphors of the plasma display so that it makes it more difficult for image retention to occur. Plasmas now even have pixel shifters that help with this. After that first month or so, you should be okay. After the first year, it shouldn't be much of an issue at all.
Plasmas of today can last anywhere from 60,000 to 100,000 hours before noticing a significant decrease in brightness. That lasts longer than CRTs. That is equal to decades of normal use. If you ran it for 24 hours a day, 365 days a year, it would still equal to around a decade. By that time, there will be new technology anyway that you'll want to switch.
Taking care of a plasma for a better picture is fine to me, but most people don't have the patience or even care.
http://askville.amazon.com/Panasonic-immune-safety-features-built-prevent/AnswerDetails.do?requestId=12466505&responseId=29457845
I really hope OLED or a similar technology comes along soon, and buries both LCD and plasma.
Nice Article... I agree the benefits of 240 hz are difficult to see even to an trained eye.
I was under the impression that on 120Hz displays motion interpolation (TruMotion, MotionFlow) was a separate feature that could be disabled, so that having a 120Hz display did not automatically mean that you lost the ability to allow film-like reproduction of material.
Then look at this article that includes some pictures that show just how bad it gets: http://www.extremetech.com/article2/0,2845,2349242,00.asp.
If you dig around online a bit more, you will find that this is a problem with nearly *all* LCDs, even at high price points.
As for plasmas sucking electricity, I have two points. First is that proper adjustment of the set drops the electricity usage markedly, because out-of-the-box settings tend to be in "blow torch mode" (WAY too bright) to compete on showroom floors with LCDs. Second point is that plasma makers have made strides recently in lowering electricity usage.
Do OLED screens have an off-angle viewing concern similar to that of LCD (standard/LED-Backlit/LED-Edgelit) screens?
Anyhow, since OLED screens are uber expensive right now, I was thinking of buying a Plasma and was also curious if CNET has a Plasma-initial-and-long-term-maintenance cheat-sheet similar to Mr. kormiko's instructions below?
120Hz and 240Hz can create a you are there effect on content like the Planet Earth Blu Ray series, especially on those long and slow panning shots but on movies...well it can make Casablanca look like Days of Our Lives. It does nothing but make sports look worse IMO.
Also thanks for pointing out that the eye or brain retains images. Just wave your hand in front of your face in a fast back and forth motion and the "image" blurs. It's our brains that need 240Hz MotionFlow processing, not our HDTVs.
- by erock1974 October 15, 2009 11:38 AM PDT
- I also dislike the "dejudder" on my Samsung 52" 120hz. With that turned off, though, the "video" look goes away in film-based sources (as others have pointed out). Hah, I haven't tried Casablanca with dejudder on, but I can imagine it looks terrible!
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