Screen Uniformity Test
Solid grays, colors and gradients to spot stains and banding.
What to look for
- Cloudy patches or darker corners on mid grays (dirty screen effect).
- Yellow or pink tints drifting across white.
- Hard lines where a gradient should fade smoothly (banding).
- Flicker or crawling dots on a single solid color.
Judge panel uniformity like a reviewer
- Start with mid gray: it exposes cloudy patches and dirty screen effect best.
- Switch to white for tints, then black for glowing corners in a dark room.
- Run the smooth gradient and the stepped banding bar to check tonal transitions.
Uniformity questions
What is the dirty screen effect?
It is a cloudy, uneven texture visible on flat mid tones, especially during sports or camera pans. It comes from uneven backlight diffusion and varies from unit to unit of the same model.
Why does mid gray reveal more than white?
White runs the backlight near maximum, which washes out small differences. Mid gray keeps the panel in its most revealing zone, where diffusion flaws and pressure marks stand out.
What does banding in the gradient mean?
Smooth gradients should fade without visible steps. Hard stripes point to low color depth, aggressive compression or heavy-handed calibration, most noticeable in dark scenes and skies.