Welcome to the MacNN Forums.

Bruck · Jan 19, 2006, 08:58 AM

Is the 20 inch fundamentally lower quality other than the normal inherent differences of a smaller display that require it to "not" have the HD specification. I've been wondering this for a long time. Is it something simple like not meeting the 16x9 spec?

jebjeb · Jan 19, 2006, 09:45 AM

I believe it is due to the 23's res of 1920x1200 which allows it to fully display both a 720p (1280x720) and a 1080i/p (1920x1080) image.

The 20" can not fully display 1080i or p.

It is not that the displays will run at the exact HD res but rather that the HD image fits on the display when it is at its native res.

mduell · Jan 19, 2006, 11:52 AM

The 23" can natively display all of the HD resolutions (720 and 1080), while the 20" can only display the lower one (720).

jebjeb · Jan 20, 2006, 09:46 AM

Originally Posted by mduell

The 23" can natively display all of the HD resolutions (720 and 1080), while the 20" can only display the lower one (720).

Mark,

Sorry to be pedantic, but I would argue about it displaying them "natively".

Native would suggest that the full pixel allocation of the display matched the HD res. My projector is 1280x720 so "natively" displays 720p HD. However, if a 20" or 23" displayed a 720p image/movie full screen, it would need to interpolate the image to fill the greater native resolution of the displays.

But you are right, the 23" can fully display both the common HD formats.

Sorry about the pickiness but resolution is something I am a bit anal about.

Bruck · Jan 20, 2006, 10:15 AM

so what you're saying is that the 20 inch has to scale down 1080i material, whereas the 23 and 30 do not?

Thanks!

Just trying to full understand the difference in quality besides size

mduell · Jan 20, 2006, 04:31 PM

Originally Posted by jebjeb

Sorry to be pedantic, but I would argue about it displaying them "natively".

Native would suggest that the full pixel allocation of the display matched the HD res. My projector is 1280x720 so "natively" displays 720p HD. However, if a 20" or 23" displayed a 720p image/movie full screen, it would need to interpolate the image to fill the greater native resolution of the displays.

But you are right, the 23" can fully display both the common HD formats.

Sorry about the pickiness but resolution is something I am a bit anal about.

There's nothing about the word native that requires the content to take up the full display area.
The 23"/24" HD LCDs can display 720p and 1080p at their native resolution; the 20" cannot (some of the 1080p content would be off the screen).

jebjeb · Jan 21, 2006, 12:48 PM

Originally Posted by mduell

There's nothing about the word native that requires the content to take up the full display area.
The 23"/24" HD LCDs can display 720p and 1080p at their native resolution; the 20" cannot (some of the 1080p content would be off the screen).

It must just be the way I read it. I have always believed that when one says that a display is natively showing a certain resolution, that it suggests that is the full physical pixel resolution of the display.
No matter, we are both saying the same thing I think anyway.

Bruck, you are spot on. The 20 is 30 vertical pixels short of 1080 and a few hundred too narrow. It has to scale it down a little. Still looks good of course but just not pixel-for-pixel.