Gray Uniformity

The Gray Uniformity test is a deep-dive diagnostic for panel illumination and manufacturing consistency. While the primary Uniformity test uses pure colors, this test uses “mid-tones” where panel defects are often much more visible to the human eye.

🎛️ Test Controls & Options

🩶 Grayscale Presets (5%, 10%, 25%, 50%, 75%): Cycle through different brightness levels using the buttons in the control panel. The 5% Gray screen is particularly famous for identifying issues on OLED panels, while 50% Gray is best for LCDs.

⬅️➡️ Navigation: Click the background to advance, or use the Left/Right Arrow Keys to jump to specific luminance levels.

📌 Status Indicators: See exactly which percentage of peak luminance you are viewing in the control panel.

🔍 Major Artifacts to Identify

1. 🫧 Dirty Screen Effect (DSE): This looks like stationary “smudges” or gray streaks across the screen. It is most noticeable during “panning” shots in sports (like a football match) or gaming.
2. 🔲 Vignetting: A darkening of the screen’s four corners compared to the center. It’s common in budget monitors but should be minimal on high-end displays.
3. 📶 Vertical Banding: Faint vertical lines that appear across the panel. On OLEDs, these “5% bands” are often visible in very dark movie scenes.
4. 🎨 Color Tinting: Even in gray, you might see “tinting” (one side looking warmer/cooler). This indicates an error in the display’s color filter or backlight diffusion.

🧠 Expert Interpretation

No panel is perfectly uniform. However, on a high-quality monitor, you should not be able to see any of these artifacts in normal daily use. If DSE or banding is visible while watching a movie or playing a game, it may be grounds for a warranty claim (Panel Lottery).

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