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Refresh rate, motion blur a nonissue on modern LCDs?

Is motion blur detectable in modern LCDs?

Eric Franklin Former Editorial Director
Eric Franklin led the CNET Tech team as Editorial Director. A 20-plus-year industry veteran, Eric began his tech journey testing computers in the CNET Labs. When not at work he can usually be found at the gym, chauffeuring his kids around town, or absorbing every motivational book he can get his hands on.
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Eric Franklin
3 min read

DisplayMate's testing lab during the LCD evaluation. 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.