OLED and LCD screen uniformity test
Click the field to fill the screen with 5% gray, then move through the gray levels and look for patches, bands, and tint.
Screen uniformity test workspace
How to use
4 short steps.
Warm the screen up and dim the room
Use the display for 20 minutes first, turn off adaptive brightness and dimming, and dim the room for the dark grays.
Click the field to go full screen
Start on 5% gray, the level that shows near-black OLED problems. Slowly scan the whole screen rather than one spot.
Move through 10%, 25%, 50%, and 75% gray
Press Space or the arrow keys, or turn on Auto-cycle to change every 3 seconds while you sit back. Turn on the zone grid to note where a patch sits.
Finish with white, red, green, and blue
White shows tint and edge falloff; the colors show a problem in one channel only.
What the result means
Match what you see to one of these.
If patches stand out during pans, that is dirty screen effect
If you see fixed darker or lighter blotches on gray that also show during sports or camera pans, the panel has dirty screen effect. Mild DSE is common on large TVs.
If you see vertical bands or blotches near black, that is mura
If 5% and 10% gray show stripes or uneven near-black areas, the panel has mura. OLED near-black mura often improves after a pixel refresh cycle.
If one side leans pink or green, that is tint
If a region matches in brightness but not in color, check white and 50% gray again. Tint is common at the edges of large LCDs.
Troubleshooting
If the test fails, try these in order.
Turn off picture processing
Disable dynamic contrast, local dimming, eye comfort modes, and adaptive brightness, then look at 25% gray again.
Sit straight on
Move only to check whether a patch follows your viewing angle, then return to your normal seat and check the gray field again.
Run the manufacturer's pixel refresh on OLED
Use the panel care or pixel refresh option in the TV menu, once, as documented. Then run the 5% and 10% gray fields again.
Check the burn-in test
If the patch is shaped like a logo, a taskbar, or a channel bug, open the screen burn-in test rather than treating it as uniformity.
What this test can't tell you
Where a browser check stops.
- The page cannot measure brightness or color across the screen or grade uniformity against a manufacturer tolerance.
- Warm-up, brightness, and picture processing all change what you see, so compare screens under the same conditions.
FAQ
Common questions about this test.
How much dirty screen effect is acceptable?
Almost every large LCD and OLED shows some DSE on a full gray field. If you do not notice it in normal content such as sports or films, it is within the usual range. If it distracts you during panning shots at normal brightness, exchange the display while you can.
Which gray level is best for an OLED uniformity test?
5% and 10% gray show near-black banding and mura, which is where OLED problems appear. Check 25% and 50% gray as well for blotches and tint.
What is dirty screen effect?
Dirty screen effect is a set of fixed uneven patches that look like smudges on a uniform image and stand out when the picture pans across them.
Does an uneven gray field mean my screen is faulty?
Not on its own. Viewing angle, reflections, warm-up, and processing all affect it. Compare under controlled conditions and judge whether it shows in normal content.