Backlight Bleed Test
Inspect light leakage and dark-screen uniformity on your monitor.
Before you start
Dim the room and keep your monitor at its normal, reasonable brightness. Sit centered at your usual distance. Inspect the black screen, then gently change your viewing position to compare any light patches.
Tap or click the plain surface to show the controls. Hide controls for a clear view; tap to recover them, or press H or Tab. Exit with the Exit button or Escape.
How to use this test
- Use the LCD at its normal reasonable brightness in a dim room, centered at your usual distance.
- Start the black surface and hide controls. Note where light patches appear.
- Change angle or distance slightly, then compare ordinary dark content. Record what remains fixed and what changes with position.
Want to compare this with timing, colors, and motion in one session? Run the Complete Monitor Test.
What to look for
Backlight bleed is light leakage that often appears near LCD edges and tends to remain in the same area. IPS glow is an angle-dependent sheen that changes with viewing position and distance. Other panel types can also shift brightness or contrast off-axis. A fixed patch and changing glow can coexist; comparing positions helps describe what you see without automatically diagnosing it.
Know the limitations
A dark room makes small differences conspicuous. Judge their effect on normal viewing, without raising brightness to extremes. Camera exposure can exaggerate light patches. This page cannot separate all causes, measure leakage, score the panel, or decide a warranty claim. OLED panels have no LCD backlight.
If a photograph looks worse than the screen
Exposure can exaggerate faint light patches. Keep the viewing position, brightness setting, and room lighting in your notes, and compare the actual effect during normal viewing. The test cannot distinguish every cause of light, determine a warranty outcome, or diagnose LCD backlight leakage on an OLED.
Common questions
How can I distinguish bleed from IPS glow?
Compare from a centered position and slightly different angles or distances. Glow typically changes with position; leakage tends to stay in the same region. This visual comparison is a clue, not a confirmed diagnosis.
Should I set brightness to maximum?
No. Use your usual reasonable brightness. Extreme settings and long camera exposures can exaggerate differences that are less relevant in ordinary use.