Motion blur and screen size/seating distance

[tomanystraydogs]

The HDguru and his latest 'motion resolution' tests:

The result, three distinct groups emerged from this test of the twenty 1080p displays. All displays in the top group were plasma HDTVs. They all had a static resolution of 1080 lines and a measured motion resolution of 830-880 lines, depending on the specific display. The next group consisted of microdisplay rear projectors, static measured 1050-1080 (depending on the display) while motion resolution ranged of 610-780 lines. The bottom group were all the LCD flat panels, with a static resolution of 400 (one panel) to 1080 lines and motion rez coming in at 360 lines (one set tested) to 600 lines. Three of the LCDs tested were 120 Hz models (one was the Sony KDL-46XBR4 reviewed here), all 120 Hz models had 600 lines of motion resolution.

So according to his findings plasmas have almost 300 more lines of motion resolution vs the best LCD's.

My question is, would your ability to see the motion resolution difference be affected by the screen size and seating distance?

Just as 720p vs 1080p depends on screen size and seating distance, perhaps some do not see the picture softening during motion on LCD's because of the screen size and seating distance?

Make sense?

[Nmlobo]

IMHO there is a difference between motion blur and dynamic (motion) resolution. Blur is an apparent streaking of an object while dynamic resolution addresses the number of lines displayed while the object is in motion. If they were the same 'creature' than plasma displays would also suffer from motion blur since they also lost lines of resolution during motion. In the same article, the HDguru stated "The stationary number where all four lines could be distinguished was recorded and then the test was repeated with the motion pattern with the area where the four lines could still be discerned as separate and not blurred together was noted. These numbers were then compared." http://hdguru.com/?p=187

Your question may be right on the mark. This article http://www.soundandvisionmag.com/hit...esolution.html states "combinations of screen size and viewing distance will "saturate" your eyes with detail to the point where any more detail in the image would not be visible."

A widely used distance/size chart http://s3.carltonbale.com/resolution_chart.html indicates that you would have to sit at 5' from a 50" display to get the full benefit of 1080p and at 7.5' before you would get the full benefit of 720p. This would indicate that the further you sit from a display the less the perceived resolution.

[brentsg]

Originally Posted by Nmlobo

IMHO there is a difference between motion blur and dynamic (motion) resolution. Blur is an apparent streaking of an object while dynamic resolution addresses the number of lines displayed while the object is in motion. If they were the same 'creature' than plasma displays would also suffer from motion blur since they also lost lines of resolution during motion. In the same article, the HDguru stated "The stationary number where all four lines could be distinguished was recorded and then the test was repeated with the motion pattern with the area where the four lines could still be discerned as separate and not blurred together was noted. These numbers were then compared." http://hdguru.com/?p=187

I consider them to be the same thing. It's a blurring or smearing effect when things go into motion. They lose focus then snap back when the movement stops. I'm sensitive to this, and I do also see this on plasma as well, just much less so than LCD.

Of course with plasma I also see the yellow/green trails in high contrast with plasma too so it's not all roses. BTW I'm mostly referring to gaming. I don't see much blur on movies or TV with either tech nowdays.

[Nmlobo]

Originally Posted by brentsg

I consider them to be the same thing. It's a blurring or smearing effect when things go into motion. They lose focus then snap back when the movement stops. I'm sensitive to this, and I do also see this on plasma as well, just much less so than LCD.

Of course with plasma I also see the yellow/green trails in high contrast with plasma too so it's not all roses. BTW I'm mostly referring to gaming. I don't see much blur on movies or TV with either tech nowdays.

Not a gamer so I can not comment on that aspect.

I understand your point but I still believe blur and resolution are different. What you describe is motion blur which is due more to pixel response and sample & hold rates. Resolution change does not mean the focus changes. Look at the quote from the article where the HDguru states he used four non-blurred lines from the motion portion of the test and compared those with four static resolution lines.

[brentsg]

Originally Posted by Nmlobo

Not a gamer so I can not comment on that aspect.

I understand your point but I still believe blur and resolution are different. What you describe is motion blur which is due more to pixel response and sample & hold rates. Resolution change does not mean the focus changes. Look at the quote from the article where the HDguru states he used four non-blurred lines from the motion portion of the test and compared those with four static resolution lines.

If the resolution change wasn't due to sample and hold then the new 120hz LCDs wouldn't have scored higher than their 60hz cousins.

[xrox]

Originally Posted by tomanystraydogs

My question is, would your ability to see the motion resolution difference be affected by the screen size and seating distance?

I think the answer would be yes because motion resolution is degraded by not only "hold-time" but also velocity of motion. For a given viewing distance an object in motion will have a greater velocity on a larger screen. This in turn leads to a higher retinal velocity while tracking the object. Which leads to more edge blur perception.

[Nmlobo]

Originally Posted by brentsg

If the resolution change wasn't due to sample and hold then the new 120hz LCDs wouldn't have scored higher than their 60hz cousins.

I don't believe they did test higher. "motion rez coming in at 360 lines (one set tested) to 600 lines." One set tested a low 360 and others up to 600. Then another sentence states that three of the sets were 120hz sets and they tested at 600 lines. Unless he tested only 4 LCDs, one 60hz and the rest at 120hz, that tells me that other LCDs also tested at 600 lines.

[brentsg]

Originally Posted by Nmlobo

I don't believe they did test higher. "motion rez coming in at 360 lines (one set tested) to 600 lines." One set tested a low 360 and others up to 600. Then another sentence states that three of the sets were 120hz sets and they tested at 600 lines. Unless he tested only 4 LCDs, one 60hz and the rest at 120hz, that tells me that other LCDs also tested at 600 lines.

Oh well we'll have to wait I guess.

I read that totally different. One was 360, and others went up from there... up to 600. It sounds to me like only the 3 120hz displays achieved 600.