I extended my desktop to my 32" Emmerson LCD TV and set my resolution to the native 1366x760 which is 720P but things still look "ugly". The text is by far not as crisp as a monitor, however a 720p TV channel or movie looks fine. Why is this? Is it because the screen is physically too big? What is the relationship between resolution and screen size. 720p looks good on a 32" TV, but what about a 60", 100", 1000000"? Is there an upper limit to the physical size compared to resolution and that is why my monitor looks ugly?
TVs, unlike computer monitors, historically enable overscan by default – they cut off a few pixels from each border of the input, and zoom in the rest. For compatibility, they do this even for digital inputs like HDMI, though most of them have an option to turn this off.
Since the image is zoomed a little, input pixels no longer correspond to screen pixels, and text ends up being blurry.
Look for a setting called "overscan", "display area: full pixel", "dot by dot", "screen fit", or similar.
- engadget: HD 101: Overscan and why all TVs do it
What is the relationship between resolution and screen size?
Horizontal or vertical Resolution / DPI = Physical screen horizontal or vertical size in inches
Computer monitors used to have 96 DPI, but that's not true anymore. Monitors with greater DPI are made.
For a 96 DPI display, the size of a square pixel is 0.01 inches or 0.26 mm.
A 32 inches 16:9 TV has a screen size of 27.9 by 15.7 inches so its DPI is 1366 / 27.9 = 49 DPI. So a square pixel's size is 0.02 inches or 0.5 mm.