How to..., HTPC, MCE

Perfect adjustment of your LCD

Pixels on an LCD

When connecting my QPVision 37″ LCD to my media center through DVI I had no problems running the native resolution of 1366×768 on the screen. This gave me one-to-one pixel mapping and a completely sharp picture.

However, my friend Staale ran into some problems that seem to be quite common. He did some tests and created a simple and very effective test pattern that can help you find the right resolution.

It seems like quite a bit of LCD screens that has a resolution of 1366×768 report to the screen cards that the correct resolution is 1360×768. Seems like a small difference, but when you run 1360×768 on a screen that actually is 1366×768 the screen sometimes does a bit of scaling that makes parts of the picture slightly unfocused.

Here is an example. The first picture is taken as a super close up of the screen in 1360×768. The next one is the same area on the same screen forced to 1366×768 through the advanced settings in the screen card driver:

Screenshot of resolution 1360x768 Screenshot of resolution 1366x768

And here is a detail of those images:

Detail of 1360x768 Detail of 1366x768

The difference seems big here, but it can be difficult to detect and that is where Staale’s brilliant test pattern comes in. It is a simple grid of black and white pixels that will clearly reveal a screen that is not mapped one-to-one. You can download the image here:

GIF (3 k)
PNG (4 k)
BMP (1,2 MB)

It should never be converted to a JPG. Any lossy compression will destroy the file.

Download it and insert it as your desktop pattern. Centered and not streched.

If your screen looks like this:

Screenshot of a perfect resolution

…then you have a perfect one-to-one pixel mapping.

If it looks like this:

Screenshot of problem with the pixel mapping

…then you have a problem with your pixel mapping.

Unfortunately it can be difficult to solve the problem. It depends on the screen, your screen card, the firmware in the screen, your screen card drivers, the software you use etc… It involves advanced tools and might even put you into serious trouble with your screen and the image from your computer.

For relatively new Nvidia screen cards and drivers you have options to take complete control of the refresh rates and resolution to the screen. You can also try playing around with PowerStrip. Or, use AVS Forum. An excellent source of information on advanced use of media equipment.

Digg this story here.

And please feel free to comment if you have solutions to this problem for specific setups.