Gradient & Banding Test Pro
The Gradient Test renders continuous and stepped (8, 16, 32, 64, 128 steps) color gradients across Horizontal, Vertical, and Radial orientations to assess panel bit-depth, gamma stability, and dithering.
- Inspect transitions across the screen for discrete lines or harsh steps (color banding).
- Toggle between Horizontal, Vertical, and Radial orientations.
- Compare Continuous mode with Stepped modes (8, 16, 32, 64, 128 steps).
- Smooth transitions in continuous mode indicate proper 8-bit/10-bit processing and accurate gamma curves.
What This Test Checks
- Color banding artifacts and discrete stepping along continuous tonal ramps.
- Display panel internal bit depth (6-bit + FRC vs true 8-bit vs native 10-bit).
- Gamma tracking and linearity from near-black to peak highlights.
- GPU output quantization range (Full Range 0-255 vs Limited Range 16-235).
How to Perform the Test
- Launch the test in fullscreen to maximize the physical pixel distance across the gradient ramp.
- Toggle between Horizontal and Vertical gradient orientations to inspect both panel axes.
- Examine the transitions between shades for smooth, seamless blurs versus visible step-like lines.
- Cycle through monochrome (Black to White) and individual color channel gradients (RGB and complementary blends).
What to Look For
- Step lines or vertical stripes where smooth tone changes should occur (Banding).
- Posterization or blocky contours, especially in dark shadow regions (near-black clipping).
- Color contamination along monochrome ramps (e.g. green or magenta tint appearing inside a black-to-white gradient).
- Temporal dithering shimmer or flickering pixels caused by aggressive FRC (Frame Rate Control).
Common Display Problems & Diagnostic Guidance
6-Bit + FRC vs True 8-Bit Panels
Many budget gaming monitors use 6-bit panels that simulate 8-bit colors by rapidly flickering pixels between two shades (FRC dithering). If the temporal dithering algorithm is suboptimal, distinct bands or pixel shimmer will be visible in smooth gradients.
GPU Limited Dynamic Range (HDMI Bug)
On Windows and Linux, connecting via HDMI sometimes causes graphics drivers (Nvidia/AMD/Intel) to default to "Limited RGB (16-235)" instead of "Full RGB (0-255)", resulting in severe crushed blacks, blown-out whites, and noticeable banding across all gradients.
Lossy Gamma Calibration Profiles (ICM/ICC)
Loading heavy 8-bit software calibration LUTs through the Windows graphics pipeline often induces banding because intermediate values are rounded off. Hardware LUT calibration inside the monitor avoids this issue.
Compressed Content vs Hardware Banding
Web videos (YouTube, Netflix) frequently contain compression banding from H.264/HEVC compression. ScreenCheck renders native 32-bit floating-point CSS gradients directly in the browser pipeline, ensuring any observed banding originates from your hardware or display driver.
Frequently Asked Questions
How do I fix color banding on my PC monitor?
Check your GPU control panel (Nvidia Control Panel or AMD Radeon Software) and verify: 1) Output Color Format is set to RGB, 2) Output Dynamic Range is set to Full (0-255), and 3) Output Color Depth is set to 8 bpc or 10 bpc if your cable (DisplayPort recommended) supports it.
What is 10-bit color depth?
Standard 8-bit panels display 256 steps per RGB channel (16.7 million colors). 10-bit panels provide 1,024 steps per channel (over 1.07 billion colors), virtually eliminating color banding across all gradients.
Why does vertical gradient look different from horizontal gradient?
LCD panel scanlines, polarizer alignment, and internal column driver architecture operate along physical axes. Switching between horizontal and vertical orientations reveals whether driver artifacts are directional.