Comprehensive black uniformity testing to reveal backlight bleeding, clouding, IPS glow, and contrast issues. Essential for evaluating display quality in dark scenes, HDR content, and professional color work.
Click below to display a full black screen. View in a completely dark room for best results. Look for any bright spots, clouding, or uneven illumination.
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Look for:
Black uniformity refers to a display's ability to produce consistent black levels across the entire screen. Poor black uniformity manifests as bright spots, clouding, or glow when displaying dark content, significantly impacting viewing experience in dark scenes and overall contrast ratio.
The most accurate method for detecting black uniformity issues:
Reveals uniformity issues not visible in pure black:
Lower percentages are more revealing of issues. If 5% gray shows problems, black uniformity is poor.
Special considerations for HDR displays:
Measure actual vs advertised contrast:
Note: Phone light meters can provide rough estimates. Professional colorimeters needed for accuracy.
Typical Contrast: 1000:1
Typical Contrast: 3000:1 - 5000:1
Typical Contrast: 1000:1
Typical Contrast: Infinite
FALD (Full Array Local Dimming) can dramatically improve black uniformity:
⚠️ Physical adjustments may void warranty
Industry Standards: Most manufacturers don't consider backlight bleed a defect unless it's visible during normal use. Document with photos in dark room at 30% brightness for warranty claims.
Requirements: Good uniformity more important than deep blacks
Requirements: Deep blacks essential for cinematic experience
Requirements: Depends on game genres
Requirements: Black uniformity least critical
Dell UltraSharp - Superior black uniformity
Achieve accurate black levels
Reduce eye strain during testing
No, they're different phenomena. IPS glow is inherent to the technology and changes with viewing angle - it appears as a silvery/golden sheen typically in corners. Backlight bleed is light leaking through the LCD panel edges and remains constant regardless of viewing angle. IPS glow is normal; excessive backlight bleed may be a defect.
Yes, backlight bleed can worsen due to heat expansion, aging adhesives, or physical stress on the panel. However, it can also improve initially as the panel "settles" after manufacturing. If bleed significantly worsens, it may indicate failing components.
OLED panels are emissive - each pixel produces its own light. When displaying black, pixels are completely turned off, producing true black with infinite contrast. LCD panels use a backlight that's always on, making perfect blacks impossible as some light always leaks through.
It depends on your use case and tolerance. If the bleed is only visible in a completely dark room with a black screen, it's considered normal. If it's visible during regular dark content viewing or bothers you, consider returning. Remember that replacement units may have similar or different issues - it's often called the "panel lottery."
Use a completely dark room, set monitor to 30-50% brightness, display a black screen, and use your phone camera with: manual mode if available, ISO 800-1600, 1-2 second exposure, camera on tripod or stable surface, taken straight-on to screen. Include a reference photo with lights on. Note that cameras often exaggerate bleed.
Black uniformity significantly impacts display quality, especially for dark content viewing. While perfect uniformity is rare in LCD technology, understanding what's normal versus defective helps set realistic expectations.
Use our testing tools to evaluate your display objectively. Remember that some issues like IPS glow are inherent to the technology, while others like excessive backlight bleed may warrant a return. The key is finding a balance between acceptable imperfections and your specific needs.
For the ultimate black uniformity, OLED remains unmatched, but modern VA panels with local dimming offer excellent performance at more accessible prices. Whatever technology you choose, proper testing ensures you get the best possible unit within your budget.