Gray Uniformity Test

Gray uniformity test is exactly what is sounds like. We take a gray color (solid image) and we put it on the screen. This test is super useful in detecting uniformity issues, because each subpixel (a tiny red green or blue component that forms a pixel) is required to perform the same task. Follow the directions below to perform gray uniformity test using our test screens and downloadable images.

Screen Gray Uniformity Test will allow you to spot irregularities in 5% and 50% gray image

Here’s how you should proceed:

• Click start button below to start testing;
• You will be presented with 5% grey screen. Take pictures (not screenshots) and inspect the screen for as long as you need to analyze 5% grey color uniformity on this screen;
• Click anywhere on the screen. You will be presented with a second image which is 50% grey screen. Once again, take pictures and inspect the screen for as long as you require to determine 50% grey uniformity;
• Read the information below on this page to learn how to judge the outcome of this test.

How this test works

Here is what we’re trying to do here:

Gray uniformity test has two steps and utilizes two tools (grey images) in order to evaluate how evenly the display panel performs.

When using 5% grey image for this test, we are trying to notice any issues like:

• Backlight bleeding – unwanted light escaping from the edges of the display. It can be particularly noticeable in dark scenes or when the screen is displaying dark content.

• Color Uniformity – Ensuring that the 5% gray is consistent across the entire screen without significant variations in color temperature.

This test helps us to identify any potential imperfections in the display’s ability to produce consistent and uniform dark shades. It’s particularly relevant for applications where accurate and consistent grayscale representation is essential, such as professional photo or video editing.

When using 50% grey image for this test, we are focusing on:

• Banding – any visible stripes or bands of different shades within the grey color. A good display should be free from noticeable banding, ensuring a smooth coverage with light grey color.

• Artifacts – Any anomalies, artifacts, or irregularities in displaying grey at 50% brightness can be caused by burn-in, dead pixels and other display panel issues.

A perfectly uniform display should show the same shade of grey consistently across the entire screen. Visible variations, inconsistencies, or imperfections in displaying a mid-level grey shade usually indicates a problem.

How to evaluate this test

Enter the full screen mode and inspect the gray image that is displayed on your screen.

Make sure to run this test in a dark room with no interior lights. Shut the doors and turn any led’s from other devices nearby (printer, tv, charger, PC etc.) It is advisable to draw the night curtains to limit the light coming into the room where this test takes place.

Tip: Take a picture. You can take some pictures while doing this test to analyze them later. Make sure to use a tripod or any other steady surface as it is highly expected to get motion blur when photographing bright objects in a dark room. Make sure not to use the flash and repeat photographing if any motion blur is visible upon initial inspection.

Analyze what you see: Look for any irregularities in solid gray image that should be covering the entirety of screen. Make sure to have this image displayed in full screen with no letterboxing or black bars on the sides.

Look for any visible banding, streaks, light or dark regions: This means that you should check the screen for non-uniform appearance including variations in lightness and color.

Banding

Color banding in gray uniformity test refers to visible, distinct bands or stripes of varying brightness that become apparent instead of a smooth and solid gray color across the screen area.

Graininess

More common with lower-end monitors or screens. Displays with lower bit depths or less precise color reproduction may struggle to represent smooth colors resulting in a grainy appearance. Various screen panel types, such as TN (Twisted Nematic), IPS (In-Plane Switching), or OLED (Organic Light-Emitting Diode), can have varying performance characteristics. Some panels may exhibit more graininess than others, particularly when displaying certain colors or gradients.

Screen gray uniformity test (50% left and 5% right)

Here are just a few example images showcasing the uniformity test of the screen.

You should notice how gray color does not appear uniform in either of these images. You can use our test images to try this test on your screen and compare the results.

What’s next?

Once you’re done testing gray uniformity, there are couple more similar tests available including long-term burn-in tests for LCD monitors, oLED TV’s and other screens here on our website. Feel free to pick any of those quick and free tests to perform here online, bookmark this site for future reference and re-run any test any time you need.