Panel Uniformity Test
Fullscreen uniform fields from 10% to 90% gray and primary colors to expose vignette dark corners, center hot-spots, and color tint shifts (e.g. pink or green cast) across the panel.
Technical Scope & Limitations
Subjective visual inspection. The browser cannot calculate numerical Delta-E or candela/m² luminance distribution without a colorimeter or spectrophotometer.
Browser rendering output can be influenced by OS display scaling, GPU driver color settings, and active HDR profiles.
- Enter fullscreen mode in a room with moderate, non-glare lighting.
- Cycle through the 10% to 90% gray fields.
- Scan the screen from edges to center for brightness drop-off (vignetting) or blotchy luminance.
- Look for subtle tint variances (e.g., warmer left side and cooler right side).
What This Test Checks
- Edge-to-edge brightness consistency across multiple luminance levels (10% to 90%).
- Vignetting: corner luminance falloff common on edge-lit panels.
- Color temperature uniformity: pink or green tint variations across the panel.
- Uneven diffuser illumination blotches.
How to Perform the Test
- Enter fullscreen mode.
- Use arrow keys or click the level buttons to step through 10% to 90% grays.
- Inspect the perimeter of the screen for dark edges or uneven brightness.
- Look for subtle color casts (e.g. left side warmer than right side).
What to Look For
- A uniform panel shows an identical shade of neutral gray across the entire active area.
- Dark corners or cloudy patches indicate backlight diffusion variations.
Common Display Problems & Diagnostic Guidance
IPS Corner Vignetting
Many IPS monitors exhibit 5%–15% luminance falloff toward the extreme corners. While normal in consumer displays, professional color grading panels utilize Digital Uniformity Compensation (DUC) to correct this.
Frequently Asked Questions
Can software fix panel uniformity?
No. Uniformity is dictated by the physical backlight array, light guide plate, and LCD cell consistency. However, identifying poor uniformity is crucial for warranty returns.