Aspect ratio question

[thesadguy]

Hope you gyus can help me

Is aspect ratio determined by resolution or physical size?

i.e. An LCD with a resolution of 1366 x 768 with square pixels has an aspect ratio of 16:9, right?

What about a plasma with a resolution of 1024 x 768 with rectangular pixels? Would we then take the physical size to determine aspect ratio? In this case, the resolution has an aspect ratio of 4:3, while the physical size has an aspect ratio of 16:9. Regardless of the shape of the pixels, there's no new information added to make the picture wider (which is what 16:9 implies, correct?). Unless the technology somehow maps 1.3 logical pixels (horizontally) to 1 physical pixel?

Thanks in advance.

 

[Saajid]

Very good question indeed - I never thought of it that way.

Aspect ratio based on physical dimensions of your screen

vs

Aspect ratio based on the screen resolution

I'm interested to read everybody's replies....

 

[SaiyanZ]

One thing I'm sure of. The quality of a 1024x768 picture compared to a 1366x768 picture will be a little lower if both screens are the same size.

I dont think you can play true 16:9 content on the 1024x768 plasma without any scaling going on and thus a slight loss in picture quality. Think of it like a PC screen. If you download a 1366x768 wallpaper and fit it to your 1024x768 desktop the wallpaper will squeeze vertically and everything will appear thinner. I think the same thing would happen with the 1024x768 plasma. A true 16:9, 1366x768 image would be downscaled to 1024 horizontal pixels but the picture would still appear as 16:9 (with a quality loss because of the downscaling and then stretching) as the pixels are rectangular.

 

[apogeeza]

First, the difference between the two terms
http://en.wikipedia.org/wiki/Technology_of_television#Aspect_ratios
http://en.wikipedia.org/wiki/Screen_resolution

notably this:

Note that the use of the word resolution here is misleading. The term “display resolution” is usually used to mean pixel dimensions (e.g., 1920×1200), which does not tell anything about the resolution of the display on which the image is actually formed.

Digital screens can expand and squeeze and interpolate incoming data to fit different aspect ratios and different display resolutions.