What happens if you change resolution on an LCD?

[Noriaki]

What happens if you get an LCD meant for 1024x768 (or worse 1280x1024 ick..) and set it to 800x600.

Do you only use 800x600 of the pixels, or does it stretch to fit the screen?

If it does stretch, does it look really bad?

 

[Davegod75]

i'm pretty sure it streches, and usually looks bad. However i've heard the newer lcds are doing a better job of handling resolutions other than default

 

[Gosharkss]

All LCD monitors are fixed resolution devices. LCD monitors use a matrix of cells so the pixels are in a fixed location and therefore define the native resolution of the monitor. For example a typical 18" LCD monitor with a dot pitch of 0.2805mm and a horizontal viewable area of 359mm has a native resolution of 1280 in the horizontal direction. Math is simple, 359 divided by 0.2805 equals 1279.85 or 1280 if you account for the small rounding error. Same calculation can be made in the vertical direction.

What happens at resolutions other than the native resolution is that the electronics must scale the smaller image up to the maximum size of the matrix or cells. The scaling is relatively easy if you are dividing or multiplying by 2 (going from 1280 to 640 for example, the height and width of the pixels are halved) but difficult when scaling by a non-integer. When the scaling factor is not an integer its not possible to uniquely assign data to a singe pixel or cell. The mathematical rounding errors can create the fuzziness or clarity problems you see.

Most LCD monitors today have complex circuitry to stretch the image across the screen and reduce this phenomenon however the odds are you will still see some artifacts at resolutions other than the native resolution.

Jim Witkowski
Chief Hardware Engineer
Cornerstone / MonitorsDirect.com

 

[Noriaki]

Hrmmm any 1600x1200 LCDs?
They should do fairly well at 800x600 then...

 

[BD2003]

If youre using a resolution that divids perfectly, the pixels will just double.

If youre using an odd resolution, it gets either stretched or made smaller. Smaller will be smaller, but it wont look crappy.

If its stretched on an old monitor, it may be ugly pixel stretching.

One a good monitor, you'll get some decent bilinear or bicubic filtering.

Still best to keep it at its native resolution.

 

[Noriaki]

a 17 or 18 inch LCD at 1024x768 or higher isn't very feasable for me...

I would like to keep it in it's native resolution but with my poor vision I need about a 21" monitor before 1024x768 is really feasable for me. That means ~20" LCD...they are stlil a tad to expensive...