1365 x 768 vs 720p or why are there no 720p TVs?

[paradox]

Hi,
I've been looking to buy myself a 50 inch plasma TV and was quite surprised to see that there are practically no real 1280 x 720p TVs around - they all seem to have a native resolution of 1365 x 768. Why is this? I would have though it would have been slightly cheaper to build them at a resolution of 1280 x 720 and it would mean they can have a shiny sticker on them saying 'True 720p!' or something. I realize that 1365 x 768 is larger but it also means the TV has to scale the image, which depending on how it is done could actually lead to it looking worse.

So my questions are why are there so many 1365 x 768 tvs out there? Will I loose any quality by buying a 1365 x 768 native resolution TV instead of a 1280 x 720 one? Should I be looking for a 1280 x 720 tv or is it going to make no practical difference?

Thanks
- Luke

 

[AVRat]

The quick & dirty answer is it's no big deal if you get a decent quality set. The best value units come from Samsung, Panasonic, and Pioneer.

 

[ragged]

Well, just my opinion, but Sharp makes a great lcd. I've had a 32" aquos for over a year and am completely happy. I decided to buy another 32" lcd for a 2nd room and bought a samsung buthad to return it. The pic was not as good as the aquos.

 

[BBigJ]

I realize that 1365 x 768 is larger but it also means the TV has to scale the image, which depending on how it is done could actually lead to it looking worse.

I've been curious about this myself. I would take the question one step further by asking if a 1080 TV has a processing advantage (PQ-wise) over a 768 unit. Obviously, the 1080 TV has to do less processing if it is getting a 1080i/p signal, but consider a 768 TV and a 1080 TV each getting fed a 720p signal. The 1080 unit has a fairly straightforward task, it need to take blocks of four pixels (2x2) and convert them to blocks of nine pixels. This seems very straightforward, the corners are unmodified, the center is an average of all four original pixels, and the middle-edge pixels are just a 50/50 mix of the two adjacent corners. The 768 TV also has to scale the image, but it isn't nearly as easy to figure out the correct pixels to average and what the correct linear combination to take is. While I'm sure the processing chip can handle this very fast (fast enough to prevent a deadly 2-3 frame lag in a video game?) the potential for artifacts is certainly greater.

 

[mtrycrafts]

Hi,
I've been looking to buy myself a 50 inch plasma TV and was quite surprised to see that there are practically no real 1280 x 720p TVs around - they all seem to have a native resolution of 1365 x 768. Why is this? I would have though it would have been slightly cheaper to build them at a resolution of 1280 x 720 and it would mean they can have a shiny sticker on them saying 'True 720p!' or something. I realize that 1365 x 768 is larger but it also means the TV has to scale the image, which depending on how it is done could actually lead to it looking worse.

So my questions are why are there so many 1365 x 768 tvs out there? Will I loose any quality by buying a 1365 x 768 native resolution TV instead of a 1280 x 720 one? Should I be looking for a 1280 x 720 tv or is it going to make no practical difference?

Thanks
- Luke

I bet to be compatible with some of the other video standards.

 

[MDS]

I don't know for sure but I suspect the reason that many TVs use an 'odd' resolution like 1366 x 768 is due to the size of the pixels. The size of the pixels and the gaps between them varies with the type of TV (lcd vs plasma vs rear projection) and it may be that 1280 x 720 (720p) just wouldn't cover the whole screen for the larger screen sizes.

When you consider that there are only a handful of manufacturers for the screens you can see why a lot of brands have the same resolution because they all source their panels from the same place.

IMO, this is a perfect example of why the whole 'upconverting' receiver/dvd players trend is much ado about nothing. If your TV has a resolution of 1366 x 768 the TV will have to scale no matter what and it won't matter one bit whether the receiver or player scales first - the TV will still have to scale as well. IFF the TV's resolution matches a standard HD resolution AND the receiver/player does a better job than the TV will having the receiver/player do the scaling improve the image quality.

Still, many of the TVs I have seen with 1366 x 768 resolution look quite good regardless of whether they are fed 720p or 1080i.

 

[mtrycrafts]

I don't know for sure but I suspect the reason that many TVs use an 'odd' resolution like 1366 x 768 is due to the size of the pixels. The size of the pixels and the gaps between them varies with the type of TV (lcd vs plasma vs rear projection) and it may be that 1280 x 720 (720p) just wouldn't cover the whole screen for the larger screen sizes.

When you consider that there are only a handful of manufacturers for the screens you can see why a lot of brands have the same resolution because they all source their panels from the same place.

IMO, this is a perfect example of why the whole 'upconverting' receiver/dvd players trend is much ado about nothing. If your TV has a resolution of 1366 x 768 the TV will have to scale no matter what and it won't matter one bit whether the receiver or player scales first - the TV will still have to scale as well. IFF the TV's resolution matches a standard HD resolution AND the receiver/player does a better job than the TV will having the receiver/player do the scaling improve the image quality.

Still, many of the TVs I have seen with 1366 x 768 resolution look quite good regardless of whether they are fed 720p or 1080i.

Some people rag about wikipedia but I find it very useful

http://en.wikipedia.org/wiki/Display_resolution

 

[MDS]

I don't rag on Wikipedia except for the few cases where I have noticed errors. I am not an expert on everything under the sun - just some things.

"An array of 1280×720 on a 16:9 progressive scanned display has square pixels. An array of 1024×768 on a 16:9 progressive scan display has rectangular pixels."

That quote is what I was getting at. Due to the size of the screen and the physical dimensions of the pixels on the panel chosen for the display, it may not be possible to use a 'standard' HD resolution and fill the entire screen.

Also note that 1366 x 768 is the computer graphics standard of WXGA. I didn't know the acronym because I stopped keeping track of the acronym vs resolution relationship a long time ago. I wonder if there is a correlation between WXGA as a chosen resolution and the fact that many of the display manufacturers are also involved in computer displays. Hmmm....

 

[obscbyclouds]

I don't rag on Wikipedia except for the few cases where I have noticed errors. I am not an expert on everything under the sun - just some things.

"An array of 1280×720 on a 16:9 progressive scanned display has square pixels. An array of 1024×768 on a 16:9 progressive scan display has rectangular pixels."

That quote is what I was getting at. Due to the size of the screen and the physical dimensions of the pixels on the panel chosen for the display, it may not be possible to use a 'standard' HD resolution and fill the entire screen.

Also note that 1366 x 768 is the computer graphics standard of WXGA. I didn't know the acronym because I stopped keeping track of the acronym vs resolution relationship a long time ago. I wonder if there is a correlation between WXGA as a chosen resolution and the fact that many of the display manufacturers are also involved in computer displays. Hmmm....

I smell a conspiracy

 

[mtrycrafts]

Also note that 1366 x 768 is the computer graphics standard of WXGA. I didn't know the acronym because I stopped keeping track of the acronym vs resolution relationship a long time ago. I wonder if there is a correlation between WXGA as a chosen resolution and the fact that many of the display manufacturers are also involved in computer displays. Hmmm....

I bet this is why the 768 numbers come from. Too many cooks in the kitchen?

 

[BMXTRIX]

I didn't look at Wiki but I can give you a pretty solid answer on this nonetheless.

You see, 1024x768 is about as standard as any PC resolution gets. When it comes to displaying text on screen you really must have perfect 1:1 pixel mapping which is what 1024x768 - or more often with 50" display - 1365x768 can deliver - albeit with black bars on the sides.

Now video, unlike a PC image, is very forgiving. Only with extremely high resolution footage and with a large enough display, will you see the difference between a perfect 720p display and a 768p display. Even then, it will be a small difference and the better displays deal with irregularities by using good processing.

In the end, the business world has been pushing the home world for many years and the standard for factories was set quite a while back when plasmas really were being bought mostly by businesses. Now, with 1080p being the driving word, the new factories are coming online with that set as the 'standard' and 768p/WXGA being fine for all those old businesses still.

42" plasmas are just whack because of their need for rectangular pixels. As far as I know, I have never seen a square pixel HD 42" plasma. LCD, yes, plasma, no.

 

[paradox]

So basically, the 1365 x 768 comes from the fact that in the past most large screen displays were sold to businesses and where they would have been plugged into PCs running at 1365 x 768 or 1024 x 768. Its odd though, because I would have thought it would be easy for a PC out just switch to a resolution of 1280 x 720.

BTW just out of curiosity does anybody know if there are any 'native' 720p displays out on the market?

 

[BMXTRIX]

So basically, the 1365 x 768 comes from the fact that in the past most large screen displays were sold to businesses and where they would have been plugged into PCs running at 1365 x 768 or 1024 x 768. Its odd though, because I would have thought it would be easy for a PC out just switch to a resolution of 1280 x 720.

BTW just out of curiosity does anybody know if there are any 'native' 720p displays out on the market?

That's basically it. But, it goes further than that. You see, many PC users split the PC signal to a local monitor as well as to a plasma. So, the 1024x768 isn't dedicated to the plasma, but is one PC of many that may be shown on the plasma. Likewise, many laptops of that era had 1024x768 monitors with them, so plugging in a plasma would default to 1024x768 most often. Finally, most websites at that time were also designed and optimized for 1024x768 resolutions.

It more or less is a decato PC standard: XGA... 1024x768 @ 60hz.

On the other hand, if you fed XGA into a 720p display, it would require scaling which would immediately hurt the image quality and make text a bit blurry to read. This is entirely unacceptable in a board room/presentation environment.

But, I do believe that with how popluar plasmas are these days that there should be some out there that are 1280x720 native.