Moving Picture Resolution - Is 1080p really 1080p?

[stuckless]

I was trying to help a friend of mine research a HDTV and I stumbled across something that I hadn't heard of before called, "Moving Picture Resolution". We were looking at a couple of TVs (in this case panasonic), they were both listed as 1080p with with a resolution of 1920x1080, but one had it's "moving picture resolution" listed at 900lines? WT??

After some googling, I found this article, which basically seems to say that the 1080p television now has 2 resolutions, still picture and moving. SO even though a TV "boasts" as being 1080p, they really just mean 1080p for watching your still image library, not ACTUALLY 1080p for video.

To me me, this just seems wrong on so many levels? Am I reading this right? Are most 1080p TVs probably not 1080p at all

[stanger89]

Asking the simple questions huh?

Originally Posted by stuckless

I was trying to help a friend of mine research a HDTV and I stumbled across something that I hadn't heard of before called, "Moving Picture Resolution". We were looking at a couple of TVs (in this case panasonic), they were both listed as 1080p with with a resolution of 1920x1080, but one had it's "moving picture resolution" listed at 900lines? WT??

Well first things first, I'd take the "Moving Picture Resolution" spec with a huge block of salt. AFAIK there's no standard, objective method for measuring it, so it's really just a marketing thing now.

But the whole idea of Motion handling is something that is real. It comes up a lot on the projector forums (probably elsewhere) over on AVS. I don't even know if I can come up with a good explanation of it, but I do know that motion handling is a very complicated topic.

Lots of things factor into motion handling, brighteness, screen size (viewing ratio), the panel technology, the video processing circuitry, the source, etc, etc.

One of the classic examples in the projector world is LCD vs DLP. DLPs have essentially "perfect" motion handling, at least from a panel tech level. The DMDs have a response time in the picoseconds, and use PWM to modulate the light, thus there is no possibility for the previous frame to "bleed" into the next one.

LCDs on the other hand, may never really turn off, they may just slightly change their opacity/polarization meaning that the few ms it takes for the change to occur, the image from one frame "slowly" transitions into the one for the next.

This is the classic LCD motion blur, like we all remember from the early days of LCD computer monitors where you'd see the mouse cursor trail as you move it. It's gotten better as panels have gotten faster, to the point where it's a non issue for some. But at the same time, it still needs work which is a large part of the reason (I think) why Frame Interpolation is so popular on LCDs.

Today it's not so much a problem with trailing, but with movement losing a bit of sharpness compared to static content. But this here is where the whole thing becomes hugely complicated. Bluring/softening of the image with movement can have several sources.

First there's the obvious panel induced "blur" that I've talked about above. but beyond that, the next, and perhaps the biggest culprit is the source itself. Quite often the blur you see with motion is part of the source, it was captured that way due to the film speed/aperture. And finally there's the issues of how we see things vs how they're displayed. It's called Sample and Hold effect, and Microsoft has a good writeup on it.

In a nutshell as your eyes track something moving across a digital display (especially a "static" LCD/LCOS display vs a "pulsed" system like DLP/Plasma) we see blur as it remains stationary for each frame while our eyes do not. But obviously the effect of SAH is largely viewer dependent.

After some googling, I found this article, which basically seems to say that the 1080p television now has 2 resolutions, still picture and moving. SO even though a TV "boasts" as being 1080p, they really just mean 1080p for watching your still image library, not ACTUALLY 1080p for video.

First it's not really two resolutions, the TV still has just one resolution, motion handling is more along the lines of contrast performance, or video processing. Better/different displays do them better/different.

Second, just because they say "motion" doesn't mean that it equates to "video". Video is made up of a combination of motion and static imagery, so just because it's "video" doesn't mean you won't get the "full" resolution. Most video content is made up of either a largely static scene with little movement (characters talking), a "static" subject with motion in the background (most action scenes where the focused character is consistenly in the center with the surroundings moving around), or maybe relatively static shot where something moves across it.

Where the issues discussed above will show themselves is most often in the sort of "medium speed" panning shots, like panning across a landscape. The sort of shot where the whole screen moves and the focus is the part that's moving. There aren't a lot of these shots in movies.

To me me, this just seems wrong on so many levels? Am I reading this right? Are most 1080p TVs probably not 1080p at all

I think you're reading too much into it. Motion issues are a problem, but it's not like you make it out where a "1080p TV only shows 720p with video" sort of thing.

The best thing you can do is go look at the TV with a variety of content and see what you think. The motion issue is much talked about in the JVC RSx threads. The RSx are DiLA (LCoS), if you read the threads you'll see plenty of people complaining about the motion handling, but you'll also find that probably many more are perfectly happy. Then there are those who spent some time investigating the issue and quite often they find that the problem is in the source.

[Taddeusz]

You also have to remember that TV's use a different subpixel mask than computer monitors. They use a triangular mask rather than the square side-by-side mask of computer monitors. For that reason resolution of a TV is somewhat of a complicated issue to begin with because there is no pixel for pixel mapping to a TV LCD as there is for a computer monitor.

As Stanger said, a lot of it has to do with the image processing capabilities of the TV.

[stuckless]

So, in your oppinion is specifying the "motion picture resolution" something relavant for a TV. ie one panasonic lists it as 900 lines and the other at 1080... to me that seems like is saying that when there is motion, the processor can only display 900 lines of resolution? Or should I just forget I read anything about this and carry on with business as usual

[stanger89]

Originally Posted by stuckless

So, in your oppinion is specifying the "motion picture resolution" something relavant for a TV. ie one panasonic lists it as 900 lines and the other at 1080...

It would be if there were some sort of standard, objective way of measuring it. But there isn't.

to me that seems like is saying that when there is motion, the processor can only display 900 lines of resolution? Or should I just forget I read anything about this and carry on with business as usual

I think Contrast Ratio (the specification, not the objective measurement) might be a good corollary, Planar specifies their 8150 at about 15,000:1, JVC specifies their RS20 at 50,000:1, but you get mixed evaluations about which one has "better" contrast.

I say if you're interested, look at both, and pick the one that looks better. I wouldn't put a lot of weight in that number.

[babgvant]

The HD Guru has a small right up on the issue and results from some test - http://www.hdguru.com/will-you-see-a...exclusive/287/

[stuckless]

Originally Posted by babgvant

The HD Guru has a small right up on the issue and results from some test - http://www.hdguru.com/will-you-see-a...exclusive/287/

Thanks, that was informative.... In my limited capacity to understand motion resolution, I still feels to me that my 1080i tv may only be showing 300-900 lines of resolution for high action videos. This seems very disappointing. In fact while i'm impressed by bluray quality video, I have a hard time seeing how much better an upscaled DVD is compared to a bluray title. I know people "swear" there is a difference, and to be honest, after spending so much money on HD stuff, I want to believe, but yet when I throw in a spiderman-3 on dvd, i am always blown away by how great it looks. I watched 3 bluray titles on the weekend, and I wasn't blown away by the difference between dvd and bluray. Maybe the "motion resolution" has something to do with this??

I'm hoping for the day that I throw in the bluray dvd and go, "wow... this is really HD".

[stanger89]

Originally Posted by stuckless

Thanks, that was informative.... In my limited capacity to understand motion resolution, I still feels to me that my 1080i tv may only be showing 300-900 lines of resolution for high action videos. This seems very disappointing. In fact while i'm impressed by bluray quality video, I have a hard time seeing how much better an upscaled DVD is compared to a bluray title. I know people "swear" there is a difference, and to be honest, after spending so much money on HD stuff, I want to believe, but yet when I throw in a spiderman-3 on dvd, i am always blown away by how great it looks. I watched 3 bluray titles on the weekend, and I wasn't blown away by the difference between dvd and bluray. Maybe the "motion resolution" has something to do with this??

I think seating distance and screen size have a bigger effect. On a 110x46" screen from about 12' back, Blu-ray is significantly better than DVD, or at least can be. Heck Blu-ray is noticably better than most broadcast HD at that size.

[babgvant]

don't forget about audio improvements in BD.

BD content is 1080p so your player (or tv depending on what you're passing in) is mucking around when it converts to 1080i, you could be losing PQ in that process.

[Taddeusz]

A standard wide DVD certainly looks much better on an HDTV. But, to me at least, BD looks much better on top of that. As Stanger said, the "resolution" you see from your viewing position has more to do with the size of your screen and your viewing distance. If you have a 32" TV and are viewing from a far distance you are unlikely to see the difference between a DVD and a BD. But begin increasing the screen size and the differences start to become more apparent. Even an enhanced upscaled DVD can't compare to a full 1080p BD. There's only so much you can do with a 480p image to enhance it.

I really think when people say that can't see a difference beween SD and HD it mostly has to do with the viewing situation. In a good viewing situation the difference between SD and HD should be self evident.

[stuckless]

I guess I'll have to get a bigger and better TV My current tv is 42" tv, that is a couple of years old now. You can easily tell the difference between SD and HD satellite, but I can only marginally tell the diff between 480p and 1080i, I gess a new TV should help with that I hope my wife buys the argument as well

[Taddeusz]

I have an Insignia 42" 1080p TV I won in a drawing (not a great TV but you can't argue with free). I think right now our viewing distance is probably about 8 feet, give or take. Using my HD200 I can definitely tell a difference between even 480p and 720p. Less of a difference between 720p and 1080p. Not sure what the moving picture resolution of it is by since it's Insiginia I'm sure it's not great. Probably on the low end of the spectrum.

Honestly, besides the resolution I think one of the biggest differences between SD and HD image quality is color. And that may in part have to do with the resolution or maybe how they master it. Colors on HD just seem to be more vibrant.

[stuckless]

I have a large open concept family room... my viewing distance is about 14 feet. So that may play a role as well. I doubt, I'll put a much larger tv there... but when i finish the basement this year, I'll get something bigger down there

[Fuzzy]

Another thing to remember is how interlaced screens show motion... because 1080i is actually 1920x540 per field, if there is fast motion, and the motion is captured in interlaced mode, the position of the moving object is shifted with each field, so what you're seeing is high speed (60 fields per second) motion, but each image is only 1920x540. Compare this to 720p, where each 60 fps image is 1280x720, and you will realize that you DO get better high-speed motion from 720p than 1080i. As said though, this is only applicable to viewing fast motion if it is shot in that particular mode.

Film, on the other hand, while displayed at 1080p on lots of displays, from blu-ray, is different. There, you get 1920x1080 full resolution every single image, so motin never really looks blurred.. the disadvantage is that film content is only 24fps, so you're never really going to see smooth fast motion like you do in natively interlaced 1080i or native 720p.

Another factor not really mentioned here in regard to motion resolution, is compression blur. MPEG-2/4 both sacrifice SOME motion clairty for their compression algorithms.. the key source of their bandwidth savings is only changing the parts of the screen that REALLY need to be changed. depending on compression rate, the determination of what NEEDS to be changed can be far from ideal, leading to blurring along moving edges.

[Taddeusz]

Originally Posted by Fuzzy

Film, on the other hand, while displayed at 1080p on lots of displays, from blu-ray, is different. There, you get 1920x1080 full resolution every single image, so motin never really looks blurred.. the disadvantage is that film content is only 24fps, so you're never really going to see smooth fast motion like you do in natively interlaced 1080i or native 720p.

Not quite true if you have a 120Hz HDTV. Then as long as you have that feature enabled you'll get smooth motion as long as it's actually being sent to the TV at 24fps. AFAIK this isn't true with the HD100/HD200 as they can't send video in the native 24fps over HDMI which is going to result in judder of film content.

[babgvant]

Originally Posted by Taddeusz

Not quite true if you have a 120Hz HDTV. Then as long as you have that feature enabled you'll get smooth motion as long as it's actually being sent to the TV at 24fps. AFAIK this isn't true with the HD100/HD200 as they can't send video in the native 24fps over HDMI which is going to result in judder of film content.

Not all 120Hz tvs do a 5:5, some do a 3:2 to 60 then double.

[Taddeusz]

Originally Posted by babgvant

Not all 120Hz tvs do a 5:5, some do a 3:2 to 60 then double.

Then what's the point of having a 120Hz TV if it won't display film content with an even pullup? I thought the whole point of having a 120Hz TV was so that film content could be displayed without judder. It makes no sense otherwise.

[babgvant]

Originally Posted by Taddeusz

Then what's the point of having a 120Hz TV if it won't display film content with an even pullup? I thought the whole point of having a 120Hz TV was so that film content could be displayed without judder. It makes no sense otherwise.

LCDs aren't great with motion, 120Hz was supposed to address that; ASFAIK having a clean pulldown is an artifact of the implementation not the driver.

I completely agree that it doesn't make sense conceptually to have a 120Hz set that behaves like that, but it probably makes a lot of sense to the bottom line for OEMs that need to be able to meet a bullet point on the spec sheet.

[Fuzzy]

Originally Posted by Taddeusz

Not quite true if you have a 120Hz HDTV. Then as long as you have that feature enabled you'll get smooth motion as long as it's actually being sent to the TV at 24fps. AFAIK this isn't true with the HD100/HD200 as they can't send video in the native 24fps over HDMI which is going to result in judder of film content.

I was not necessarily referring to the 24Hz on 60Hz display problems. I was simply meaning that you will NEVER get as smooth a motion for high-action on 24hz film material as you will on 60Hz video, simply due to the lower frame-rate. Of course, I was assuming any 24hz material you WOULD be watching would actually be displayed at 24Hz. Also, I thought the HD200 was capable of outputting 1080p/24 (don't know for sure, though, as I don't use one). If not, there's yet another reason for me to stick to a real pc for playback...

Also realize, that while 120Hz is designed for better 24Hz display, most people do not know that, because it is not a part of ANY marketing. 120Hz displays are marketed as though they somehow show you more individual frames per second (examples being the Samsung football themed 120Hz commercials). Most (nearly all) consumers believe this, and know NOTHING about 24Hz source material. I can think of a couple 120Hz displays I've seen that won't even accept a 1080p/24 signal. These sets sell just fine.

[stanger89]

Originally Posted by Fuzzy

I was not necessarily referring to the 24Hz on 60Hz display problems. I was simply meaning that you will NEVER get as smooth a motion for high-action on 24hz film material as you will on 60Hz video, simply due to the lower frame-rate. Of course, I was assuming any 24hz material you WOULD be watching would actually be displayed at 24Hz. Also, I thought the HD200 was capable of outputting 1080p/24 (don't know for sure, though, as I don't use one). If not, there's yet another reason for me to stick to a real pc for playback...

It is, works great. You just have to add the custom resolution. Native output switching on the HD200 works WAY better than trying to get anything close working on a PC.