Hey guys

I’m confused about the whole 100/120Hz picture processing hype. From my understanding, motion blur is not caused by low frame rate but rather by the camera’s shutter speed. I mean, you can shoot a moving car at 5fps with shutter seeped of 1/500 second without any motion blur at all.

So how does the new LCD reduce the motion blur, by lower the ‘hold-time’ of the active matrix?

PS: The black frame insertion method isn’t worth it as it causes CRT like flicker effect. And the frame doubling technique causes motion artifacts and pixilation.

Hey guys

I’m confused about the whole 100/120Hz picture processing hype. From my understanding, motion blur is not caused by low frame rate but rather by the camera’s shutter speed. I mean, you can shoot a moving car at 5fps with shutter seeped of 1/500 second without any motion blur at all.

So how does the new LCD reduce the motion blur, by lower the ‘hold-time’ of the active matrix?

PS: The black frame insertion method isn’t worth it as it causes CRT like flicker effect. And the frame doubling technique causes motion artifacts and pixilation.
It seems at least a couple of reviewers disagree with you. And these reviews were on first generation 120Hz sets. Second generation sets will start to hit the streets within the next few weeks.

"Where the 120hz Clear Motion Drive makes a difference is with moving images, like rolling text across the screen. This is where many LCD TVs fall short, so the fact that text is crisp with defined edges (as opposed to blurred edges) when moving is hugely critical. This is something I can't overstate. This is great when watching a moving person, like with sports or in an action movie." http://tv.about.com/od/lcdproductre...VC_LT37X987.htm

"For those of you, like me, who have an aversion to motion blur, this is a big step in the right direction." http://hometheatermag.com/lcds/1106jvclt37x987/

One manufacturer claims that their processor "detects image data from more than 8,000 surrounding dots in a frame to create a pixel and calculate movement from the current frame to the next. This process is performed on all two million pixels (1920 x 1080) in a frame to interpolate for movement in all directions."

Another states: 'In the first step of the process when input signal is converted from 24Hz or 30Hz to 60Hz, our TVs will also perform what is called Motion Compensation. As you know, to convert 24Hz or 30Hz into 60Hz, the TV will insert additional frames. (The) TVs will apply an algorithm to each of these new frames that estimates a mid point between the original frame and the following frame, therefore eliminating judder, which is a common side-effect of the traditional 3:2 pull-down in the traditional 3:2 pull-down, each new frame is simply a copy of the previous frame. "

Computer generated images doesn’t have motion blur (unless it was purposely introduced). So this has to do with the LCD’s hold-up time, which is 16.6ms (1000/60 = 16.6). So by reducing it to 8.3ms, they were able to reduce the afterglow?

I do see how it can be done in any other way since you can’t remove motion blur that's already present on the video

Hey guys

I’m confused about the whole 100/120Hz picture processing hype. From my understanding, motion blur is not caused by low frame rate but rather by the camera’s shutter speed. I mean, you can shoot a moving car at 5fps with shutter seeped of 1/500 second without any motion blur at all.

So how does the new LCD reduce the motion blur, by lower the ‘hold-time’ of the active matrix?

PS: The black frame insertion method isn’t worth it as it causes CRT like flicker effect. And the frame doubling technique causes motion artifacts and pixilation."Hold time" or "Display Time" is a significant factor in our motion blur perception. And now that current LCDs have short enough response times, hold-time becomes the dominent factor which determines motion blurring.

see paper (http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=DTPSDS000036000001001590000001&idtype=cvips&gifs=yes)

The reason we see blur due to hold-time is that motion video is made up of sequential still images but our eyes tend to follow movement continuously. So the longer the pixel stays "on" the more blur is created on our moving retina. This is why 120Hz was developed - to shorten the time each pixel is "on".

for a more detailed explanation refer to the following link:

link (http://archive2.avsforum.com/avs-vb/showthread.php?t=760849&highlight=120Hz)

Computer generated images doesn’t have motion blur (unless it was purposely introduced). So this has to do with the LCD’s hold-up time, which is 16.6ms (1000/60 = 16.6). So by reducing it to 8.3ms, they were able to reduce the afterglow?

I do see how it can be done in any other way since you can’t remove motion blur that's already present on the videoYes. Reducing hold time to 8.3ms would reduce the perception of blur.

What about CRT, DLP,LCoS, LCD projection and plasma, how are able to display smooth motion without interpolating frames or black frame insertion? I mean, they are simply refresh the same frame for several times, right?

What about CRT, DLP,LCoS, LCD projection and plasma, how are able to display smooth motion without interpolating frames or black frame insertion? I mean, they are simply refresh the same frame for several times, right?It is no coincidence that the hold-time for different technologies correspond with the generally accepted motion performance quality of these technologies. For instance it is generally accepted that CRT has the best motion portrayal followed by plasma then by LCD(120) then by LCD(60). It is also thought that OLED and SED will be equal or better than CRT if used in a passive matrix manner.

HOLD TIMES(for various technologies, correspond to motion performance, from shortest to longest)

PMOLED - microseconds
PMSED - 1.5 ms
CRT - 1.5ms
Plasma - 4-6ms
LCD (120Hz) - 8.3ms
AMOLED(60Hz) - 16.7ms
LCD (60Hz) - 16.7ms

Note: I did not list DLP or LcOS as I don't know that much about those technologies. I do know that DLP uses PWM similar to plasma but I'm not sure on the hold times.

What about the new Total Matrix Addressing (TMA) for OLEDs? Will that keep the home-time down?

I'm back again with good new


I found a PDF containing everything about hold-type displays.

http://smdl.snu.ac.kr/Lecture/display1/AdvancedTechnologySeminar-1.pdf