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Sports look better in 720p?

supertankman
01-01-2005, 09:45 PM
I am still awaiting my Toshiba 46h84 to be delivered on monday, I was reading a article about how 1080i has the highest resolution but isnt as smooth as 720p because it (1080i) cant handle motion as good. ESPN decided to go with 720p because of this, I watch alot of sports and was wondering if anyone noticed any ghosting etc. when watch ESPNHD?

rbinck
01-01-2005, 09:59 PM
I can't say there is much difference in ABC/ESPN/FOX at 720p and CBS at 1080i. What seems to matter more is the bandwidth (or lack thereof) the different providers have. Our PBS station is very bad with motion.

Micmax
01-01-2005, 11:22 PM
I see ghosting/flickering more when watching 1080i, which has a hard time with backgrounds movings (crowds for one). 720p, to me, cuts down significantly on the ghosting.

I still like 1080i more than 720p. I want higher definition, not necessarily "high motion."

Sport73
01-03-2005, 09:14 AM
I am still awaiting my Toshiba 46h84 to be delivered on monday, I was reading a article about how 1080i has the highest resolution but isnt as smooth as 720p because it (1080i) cant handle motion as good. ESPN decided to go with 720p because of this, I watch alot of sports and was wondering if anyone noticed any ghosting etc. when watch ESPNHD?

There are many, many, many raging debates on this topic and the merits of the 2 current HD standards. Suffice it to say that while 1080i is 'technically' higher in pixel count, 720p actually displays more pixels at any given instant because they're all being shown at the same time, while the interlaced signal of 1080i shows only half the lines at any instance.

This can lead to noticeable motion artifacts, especially on fast moving objects (like athletes or a ball during a sporting event) because while the initial 540 frame is being drawn, the object moves before the alternate/additional 540 lines can be drawn, resulting in blurring. This is the reason why ABC/ESPN decided to endorse/use the 720p standard (along with Fox Sports).

rbinck
01-03-2005, 10:41 AM
Most of the arguements are based on the traditional SD TV displays and computer monitors. They are particularily based on a raster scan type display. Most fixed pixel displays will eliminate a great deal of the issues of interlaced vs progressive. Since fixed pixel displays are progressive by their nature, the picture is built in a pixel array memory that is then transfered to the display in a progressive manner. Once a pixel is "on" it will remain on until it is turned "off" on a sucessive update. There is not any decaying of phosphers to contend with, so the issue about only half the pixels being shown at any given time will drop out of the issue as they are all being displayed. On CRT type displays the phospher persistance and excitation cutoff is such that all of the pixels will be lit for the most part, although there is some difference between scans.

Motion blurring is one thing, but at 1920 x 1080 it becomes very difficult to distinguish from the bluring effect due to pixel straddling. Excerpt from http://members.aol.com/ajaynejr/vidres.htm

Pixel Straddling


(Affects resolution of the recording of live subjects, also the net resolution after scaling of the picture to different pixel dimension.)

Some cartoons are generated directly on computer screens. For them, picture details may be consistently lined up with the pixels, and for a 720 x 480 pixel DVD frame, the resolution can be consistently 720 x 480.

For the televising or recording of live subjects, the scan lines and (for digital video) the pixels horizontally will not consistently match up with fine details in the subject material. This can be seen if the camera is panned across details that are as fine as the pixels, those details will change from sharp to blurred to sharp again. For this reason, there are some people who will say that a 720 x 480 video frame has far less than 480 lines of resolution vertically or 720 pixels across horizontally.

As we mentioned earlier, a pixel or a small stretch of a scan line must be all one color. Going back to an earlier example of looking at a scene through a silk screen and painting it on canvas one dot at a time, if there is both black and white showing through the same hole in the screen, you have to choose the in between color of gray.

In the diagrams below we show some examples of pixel straddling in the horizontal direction. A moire pattern is the result of picture details going in and out of straddling (in and out of phase with the pixels) over a large area.

Of course we can use twice as many pixels or scan lines to eliminate the straddling but sooner or later the bandwidth needed for the video signal is too large to fit in the allotted broadcast channel or the amount of data is too large to fit on the DVD.




Pixel (http://members.aol.com/ajaynejr/vidres.htm#StraddleEx) Straddling Examples (greatly enlarged)

http://members.aol.com/ajaynejr/resol2.gif Original source is on top, video representation is on bottom. The red and white dashes along the top denote the pixel positions.



Bluring from pixel straddling can be as much or more than the bluring due to interlacing and with the naked eye you don't necessarily know the difference. In fact should the object line up on one pass to the next, the motion blurr can actually be decreased because of one pass being sharp, whereas with progressive scan there is only one pass, so it will just be blurred.

Also the effects of resolution is not given the full weight when this subject is discussed. Take a 40" wide (not diag.) HDTV screen for example. It will be made up of 1920 pixels wide or 1280 pixels wide. This would translate to a pixel width of .021" and .031" respectively. Right there you have a 33% better chance of not getting pixel straddling with the 1920 pixels. The vertical chance difference is also 33%, so the motion blurr is not the only thing to consider. In fact since the motion is normally not covering the entire screen, the pixel straddling blur could effect the overall picture more than the motion blur. Sports would be the opposite as the background tends to be the motion more so than the subject as the camera follows the subject.

Also with 1920x1080 having 33% more total pixels than 1280x720, the motion blurring is less noticeable than the difference would be if they were both being at the same resolution.

The biggest problem with 1080i is bandwidth, or the lack thereof. Most motion distortions are not blurring, but rather pixellation due to insufficient bandwidth. This is the station's choice and if you live in an area where they are compressing your 1080i signal to the point that fast moving objects end up a bunch of small boxes, it is the station, not the technology. Small boxes is pixelation not blur.

In side by side blind (excuse the pun) tests there have been studies that most people could not tell any difference in the two formats.

HighdefDoug
01-03-2005, 10:42 AM
As a Steeler's Fan, almost all games on CBS, I can tell you without a doubt that their feed/display at 1080i certainly has more flickering than abc, espn or fox. I never notice it on CSI, but always see it on the games they televise. Oddly enough, they also seem to only select a game or two each week for true HD, the rest are 4:3 SD Garbage.

Luckily the Buffalo Steelers game was high def this week. I flipped back and forth between the fox late games and the cbs late games with several folks watching the games over at my house, they also noticed the difference.

BTW, espn and abc (same network), have an even stronger offering than the fox hd, but it is probably a bias since the coverage, sound effects, etc...are just more complete and entertaining.

rbinck
01-03-2005, 11:16 AM
Yes most likely it is the station's choice of the amount of bandwidth allowed to the HD sub channel.


My NBC station has the bandwidth somewhat restricted here in Houston. The Olympics showed up the problem the best. Diving was unwatchable. Don't know for sure, but I suspect the reason is they have three subchannels going. 2-1 is the HD subchannel, 2-2 is weather and 2-3 is Doppler radar. With 3 programs having to share the bandwidth, the HD gets clipped from time to time. Funny thing is, the CBS and ABC stations also have 3 subchannels, but they don't seem to have the problems the NBC station has.

raptor
01-03-2005, 12:07 PM
I must not know or have noticed what "flickering" is when watching games in 1080i but I prefer the games on 1080 rather than 720p.

brianwat
01-03-2005, 01:42 PM
What I've found is that I get a better picture when I switch my Cable Box to the 720 format when watching ABC,Fox,ESPN and I switch it to 1080I when watching one of the other HD channels(CBS,NBC,HBO,etc.). This is something your Box should allow you to do.