What each pattern checks
| Pattern | What to look for |
|---|---|
| Uniformity (dark and mid grey) | Bright or dark patches, clouding, colour tints in parts of the screen |
| Black level | All boxes from about 3 upward should be visible against black |
| White level | Boxes up to about 252 should be visible against white |
| Gradient | Smooth fades. Visible stripes mean banding |
| Gamma | The box whose centre blends into its frame shows your gamma. 2.2 is standard |
| Sharpness | Crisp text and even fine lines, no halos |
| Colour bars | Clean, saturated colours and natural skin tones |
Before you start
- Let the monitor warm up for 15 to 30 minutes.
- Use the native resolution and 100% scaling if you can, so the patterns are drawn pixel for pixel.
- Turn off Night Light or Night Shift, and any dynamic contrast or eco mode in the monitor menu.
- Sit at your normal distance, straight in front of the screen.
Fixing common problems
- Black boxes disappear: the black level is crushed. On a PC connected over HDMI, check that the graphics driver sends Full RGB range (0 to 255), not Limited, and that the monitor expects the same.
- White boxes disappear: lower the contrast setting.
- Banding in the gradient: turn off sharpening and image enhancement, and set the graphics driver to 8-bit or 10-bit colour.
- Wrong gamma: pick a 2.2 gamma or sRGB preset in the monitor menu.
Also check for faulty pixels with the dead pixel test, and for backlight bleed with the black screen.
Frequently asked questions
Short answers to the questions people ask most about this test.
How do I test a new monitor?
Run the monitor test patterns, the dead pixel test and the black screen for backlight bleed. Most shops accept returns in the first days, so test right away.
What is gamma on a monitor?
Gamma controls how bright the midtones look. Most content is made for a gamma of 2.2. Too low looks washed out, too high looks dark and contrasty.
What is banding?
Banding shows as visible steps in smooth colour gradients. It comes from low colour depth or image processing in the monitor or graphics driver.