This visual check can help when you are evaluating a screen before buying it or deciding whether to return it. For a useful comparison, begin with the monitor settings and room conditions you want to assess, then change only one setting at a time.
How to use Black Level Test
- Select Start Test to show the pattern. Under Pattern mode, choose Nine patches or Nine bars.
- Compare the dark patches with the black background, and use the outside legend to identify their digital values. The black patches are 0, 2, 4, 6, 8, 12, 16, 24, and 32; the white patches are 224, 232, 240, 244, 248, 250, 252, 254, and 255. Read the values from left to right, then top to bottom. Each black patch uses the listed value for all three RGB channels.
- Select Previous or Next, or press Left or Right, to move between patterns. Press Space to start automatic mode. Reduced motion keeps progression manual.
- For a larger view, select Fullscreen or press F. In fullscreen, you can also tap the left or right half of the screen to move between patterns. Legends remain outside fullscreen; on phones, an Exit button stays on screen.
- Select Reset or press R to reset. To leave fullscreen, press Escape or select Exit fullscreen.
When to use it
- Before a return window closes: Check whether a new display shows separation between its darkest patches.
- When considering a used monitor: Look for dark detail that appears blended into the black background.
- After adjusting brightness or contrast: Compare the patterns to see how your adjustment affects near-black shades.
- After changing gamma or color management: Check how those changes affect the same labeled patches.
- After moving a screen to another room: See how the new ambient lighting affects your view of the dark shades.
- When comparing two displays: Use the same pattern and similar viewing conditions to compare their visible dark detail.
- During a quick check for dark-screen issues: Use the pattern as an initial visual check before pursuing a more focused test.
Tips for a useful comparison
Keep your viewing position and room lighting consistent when comparing settings. Shade visibility depends on brightness, contrast, gamma, color management, and ambient light, so change one setting at a time if you want to see what made a difference.
Use the outside legend to identify values rather than estimating them from appearance. The near-white patches can also show whether bright shades look distinct, but the main purpose of Black Level Test is to inspect near-black detail. Stop if bright patterns cause discomfort.
Limits of Black Level Test
Black Level Test is a visual pattern check, not a calibrated measurement. It does not measure black luminance or provide a precise brightness reading, and what you see depends on display settings and room light. Treat it as a way to compare visible differences, not as a definitive diagnosis of a screen.
If you want a wider set of visual checks, try the Monitor Test. For a pixel-specific check, use the Dead Pixel Test. If a concern persists, ask the display's seller or manufacturer about further assessment.