Grayscale Banding and Panel Uniformity

A gray gradient is the most revealing thing you can put on a screen, because it shows up problems a solid color hides completely. It also catches a lot of people out: what looks like a failing screen is very often the picture being sent to it.

What banding looks like

Instead of blending smoothly from black to white, the gradient breaks into visible bands: flat strips of one shade with a clear edge where the next one starts. Mild banding only shows in the darkest steps; heavy banding turns the whole fade into a staircase. In everyday use it looks like rings in a sunset, blocks in a dark film scene, or contour lines in a plain colored background.

Why it's often the signal, not the screen

Check the free fixes before you blame the screen:

• Color depth. An 8-bit signal has 256 levels per color, and across a wide gradient the gap between neighboring levels becomes visible.
• Graphics settings. Windows or your graphics driver may be sending fewer levels than your screen can show, or a limited rather than full RGB range.
• The cable. A cable or port that can't carry your resolution and refresh rate at full color depth will quietly drop to a lower one.
• Video compression. Streamed video bands badly on its own, so a video clip is never a fair test.
• Picture processing. Dynamic contrast, black-level tweaks and heavy sharpening all squash nearby shades together.

Turn those off, make sure your output is set to full RGB at the highest color depth your connection supports, and run the Banding & Uniformity Check again before you decide anything.

Uniformity and tint

Banding is about the steps between shades; uniformity is about whether one shade looks the same across the whole screen. On a flat gray screen, look for areas that are brighter or darker than the rest, or that lean warm or cool, like one edge slightly pink and the middle slightly green. Faint cloudy patches are what's called the "dirty screen effect", most obvious when a camera pans across an ice rink or a football pitch. Every LCD has some variation, because an even mid-gray is the hardest thing for a backlight to hold, and this is what people mean by the "panel lottery": two identical models can look noticeably different.

What's worth doing something about

Settings and cables cost nothing to fix, so try those first. Real banding or a strong tint that's still there whatever you plug in is a matter of degree rather than a clear fault, which makes warranties awkward. Manufacturers publish limits for faulty pixels, as listed in the manufacturer policy comparison, but they rarely have a standard for uniformity. Your return window is usually the real remedy, so judge a new screen early, using things you actually watch.

None of this is about individual faulty pixels. If the gradient also shows a fixed dot that ignores the shade behind it, run the full test and read dead vs. stuck pixels.