Banding Test

How to use it

1. Keep Smooth selected and open full screen.
2. Step through the gradients and look for stripes, steps or blotches, especially in the dark part and in the blue sky gradient.
3. Switch to 64, 32 or 16 steps to see what obvious banding looks like, then go back to Smooth and compare.
4. The shadow and highlight steps stretch the darkest and brightest 41 levels across the screen. There you should see even stripes by design: check that none are missing or merged.

A smooth 0 to 255 ramp across a wide screen has each level about as wide as the screen divided by 256. On a 3840 px wide screen that is 15 px per level, so very faint lines can be visible even on a perfect 8-bit screen, especially up close. What you are looking for are steps that are uneven, tinted or much wider than their neighbors.

What causes banding

• Panel bit depth. Some cheaper panels show fewer shades natively and fake the rest by flickering between neighbors (FRC). That usually works well, but can show as faint banding or shimmer.
• Settings that remap colors. Night light and blue light filters, low contrast or brightness set in software, color profiles and calibration curves all squeeze 256 levels into fewer, which leaves gaps.
• Picture processing. TV modes such as dynamic contrast, and some HDR tone mapping, can create bands in skies and shadows.
• The content itself. Banding in a video or photo may be in the file, from compression. This test is clean, so it tells you whether the screen adds its own.

How to reduce banding

• Turn off night light or blue light filters and test again.
• Set brightness and contrast on the monitor itself rather than in software.
• Use the full color depth your cable and graphics card support, set in the graphics driver.
• On a TV, try the PC or game mode and turn off dynamic contrast.
• Some TVs have a gradation or smooth gradation option that hides banding in video.