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Why Should You Run This Test?

A gray uniformity test reveals backlight bleed, clouding, hotspots, and IPS glow — issues that are invisible on colorful content but distracting during dark scenes in movies, games, or photo editing. If your screen looks unevenly lit, this test confirms and localizes the problem.

Common Symptoms

• Dark movie scenes show bright patches in corners or edges
• Photo editing reveals brightness inconsistencies across the canvas
• Gaming in dark environments shows distracting bright spots
• One side of the screen appears brighter than the other

What Causes Brightness Non-Uniformity?

Backlight Issues (LCD only)

• Backlight bleed — Light leaks around the edges where the backlight meets the LCD panel frame. Worse on IPS panels and visible as bright edges on dark content.
• Clouding (mura) — Uneven pressure on the LCD layers creates cloudy bright spots, usually in the center. Common in larger panels and can worsen with temperature changes.
• Hotspots — Individual LEDs in the backlight array may be brighter than others, creating visible bright dots.

Panel Issues

• IPS glow — A silvery/warm glow visible in corners of IPS panels when viewed slightly off-angle. Normal behavior but varies in intensity between units.
• Manufacturing variance — No LCD panel is perfectly uniform. Some variation is normal; excessive variation is a defect.
• Physical pressure damage — Pressing on the screen or improper mounting can create permanent bright/dark spots.

How to Read Your Results

How to Improve Gray Uniformity

• Reduce brightness — Backlight bleed and clouding become less visible at lower brightness settings. Set brightness to 30-50% for dark room use.
• Enable local dimming — If your monitor has local dimming zones, enable it to reduce backlight bleed in dark areas.
• Check mounting pressure — If using a VESA mount, ensure it's not putting excessive pressure on the panel. Loosen mounting slightly if you see pressure spots.
• Gentle massage technique (risky) — Some users gently massage clouding areas with a soft microfiber cloth to redistribute liquid crystal alignment. This is risky and may worsen the issue — proceed with caution.
• Temperature normalize — Clouding can temporarily worsen when the monitor is cold. Let it warm up for 30 minutes before testing.
• Warranty claim — If uniformity is severely poor, document it with photos and contact the manufacturer. Many have brightness uniformity standards for warranty coverage.