Originally posted by: lowtech
Why are LCD monitor only have good image display at only one resolution?
I have a 17in Acer LCD monitor that is tack sharp at 1024x1286, but the quality drop if I lower the resolution to 768x1024 to get larger text size?.
On LCD monitors the pixel pitch multiplied by the resolution defines the screen size of all LCD monitors. Thus they are a fixed or native resolution devices. For example a 15? LCD has a pixel pitch of 0.3mm and 1024 horizontal resolution. 1024 x 0.3 = 307mm horizontal. 768 x 0.3 = 230mm. Using Pythagorean theory this works out to 15? Diagonal.
Since LCD monitors have a fixed number of cells or pixels across and down the screen the electronics in the monitor must scale the image up or down when you change off of the native resolution. 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 fuzziness or clarity problems you will see.
While the scaling algorithms have gotten better there is still a noticeable degrading of image quality if you run off the native resolution. At least there is to me. Some people may not be as picky as I am as in the case you mention. It also depends on the application you use.
The scaling affect will be much less noticeable in games, animation and applications where there is movement on the screen. However it will be very noticeable with static images like a document with text.
For optimum image clarity always run your LCD monitor at its native resolution. Remember that most operating systems allow you to scale fonts and Icons to larger sized to offset the native resolution issue.
I suggest you check out
PixelSharp a new FREE software that tool automatically sets your Windows operating system to make your LCD monitor look its best. If you want to test for dead pixels, try this
Monitor ToolKit