You’ve probably heard that it’s important to use your display’s native resolution – assuming you’re using an LCD flat-panel monitor instead of an ancient CRT monitor. With a LCD, using a lower resolution will result in inferior image quality.
Windows generally defaults to your monitor’s native resolution, but many PC games will often default to lower resolutions.
Image Credit: Kevin Collins on Flickr
Effects of Using a Non-Native Resolution
You can see the effects of using a non-native resolution yourself if you’re using an LCD monitor. Right-click your desktop and select Screen resolution. From the window that appears, click the Resolution box and select a resolution other than the one recommended for your monitor (this is your monitor’s native resolution).
After selecting a lower resolution, you’ll see its results. Fonts and images will be blurry and everything will generally look lower-quality and less-sharp. This is very different from how a CRT (cathode ray tube) monitor worked. With an old CRT monitor, you wouldn’t see worse image quality when using a lower resolution.
LCD vs. CRT
In a CRT, an electron gun shoots a stream of electrons that is filtered to become the image that appears on your screen. The exact details behind how a CRT monitors work is beyond the scope of this article, but the important point is that a CRT monitor can display an image at any resolution at or below its maximum resolution. When an 800×600 signal is sent the the monitor, it produces an 800×600 image that takes up the full area of the screen.
Image Credit: Johannes Freund on Flickr
Unlike a CRT monitor, a modern LCD display contains a certain number of individual pixels. Think of each pixel as a small light that can be one of several colors (it actually produces a color through a combination of its red, green and blue elements). The image on your screen is built from the combination of these pixels. The number of pixels in an LCD results in its native resolution – for example, a laptop with a 1366×768 resolution has 1366×768 pixels.
Image Credit: Ryan Tir on Flickr
When an LCD monitor runs in its native resolution – 1366×768 in the example above — each pixel on the LCD corresponds to a pixel in the image sent by your computer’s video card. This produces a sharp, clear image.
What Happens When You Use a Non-Native Resolution
Now, imagine that your computer’s video card sends an 800×600 image to a 1366×768 LCD — you’ll see that the 800×600 image doesn’t evenly correspond to the number of pixels in the LCD. To produce an image smaller than its native resolution, the display would still be using 1366×768 pixels – so the display must interpolate (scale) the image to be larger and fill the screen. In the example here, the aspect ratios (4:3 for 800×600 and 16:9 for 1366×768) are different – so not only will the image be enlarged, the image will be distorted.
This is similar to enlarging an image in an image-editing program – you’ll lose clarity and, if the image is a different aspect ratio, it will appear distorted. For example, here I’ve taken a screenshot of How-To Geek at 800×600 and enlarged it to 1366×768 (I then shrunk it, maintaining the aspect ratio, so it would fit this article.) As you can see, the image is blurry from being enlarged and distorted from being widened. This is what your LCD does when you use a non-native resolution.
When playing games on an LCD, bear in mind that using your native resolution is important for graphics quality – although other settings may be more important, as producing a larger image takes more graphics horsepower.
If you want fonts and other elements on your screen to be larger and easier to read, you should try adjusting the size of the elements in your operating system rather than changing your monitor’s resolution.