Is a 4ms response time it really noticable it if the television that already has 120hz??

Question

Is a 4ms response time it really noticable on a set that already has 120hz?

What's the difference?!

Answer 1

Motion blur occurs because of the way LCD TVs work. The old CRT (tube) TVs, DLP & Plasma TVs all momentarily flash an image on screen. Between the flashes, the image is allowed to decay or is removed from the screen. LCD TVs work different. They present a frame on screen & then leave this image on screen until the next frame is presented (this is called sample & hold). This latter approach allows our brains to perceive motion as being blurred on an LCD because our brains see the moving objects but they do not change location (move) during an LCD TV's hold period (16.67 ms at 60 Hz).

The idea behind 120 Hz is to interpret the location of moving objects and refresh their location on screen more often so that our brains do not perceive motion blur (reduce the hold time). Using only faster LCDs will not eliminate motion blur because of LCD TVs frame presentation technique (sample & hold). Faster LCDs allow for faster image changes and helps reduce jitter but not blur. So is a 4ms LCD time noticeable? Yes, it greatly reduces jitter but 120 Hz is still needed to reduce blur. The ability of the 120 Hz processor to correctly interpret motion and accurately create the intermediate frames without producing artifacts (triple ball effect or ghosting, pixelization, etc.) is what will separate the best 120 Hz solutions from the pretenders.

P.S. The 2007 Sony XBR's offer 120 Hz "Motion Flow" but only use 8 ms LCDs. They have lots of jitter! Just watch fast moving credits with Motion Flow set to any level and you can see the jitter. Jitter seems to be more pronounced on the 2007 XBRs than on any other 120 Hz machine I've viewed to date.

Answer 2

One reduces LAG....the other sharpens the detail by refreshing it more...

There is  a difference in what both do....

So the response time gets rid of lag and smear in fast motion, and the refresh rate Sharpens/focuses high speed motion.