Background
Black crush, white clipping, and contrast
A well-set display shows the difference between nearly black and black, and between nearly white and white. When those near-black or near-white steps merge, detail disappears: shadows in a film turn into flat black blobs, or clouds lose their texture. The step patterns on this page show where your screen starts to merge them, and the most common causes are settings you can change.
Black crush and raised blacks
Black crush means the darkest steps all look identical to pure black. Common causes are a gamma setting that is too high, a dynamic contrast or eco mode, or the wrong RGB range. The opposite problem is raised blacks. Black looks dark gray, the image looks washed out, and every step is visible but nothing is truly black. That is often caused by a brightness or black-level setting that is too high, or again by an RGB range mismatch.
Gaming presets such as Black Equalizer, Dark Boost, or Shadow Boost deliberately brighten dark steps so enemies are easier to see in shadows. That is useful in some games but makes films look gray.
The RGB range mismatch
Computer graphics use full range, where black is code 0 and white is 255. Video and TV signals traditionally use limited range, where black is 16 and white is 235. When the source and the display disagree, the picture breaks in a predictable way.
If a PC sends limited range to a display expecting full range, black arrives as 16, so blacks look gray and whites look dim. If a PC sends full range to a display expecting limited range, everything below 16 becomes black and everything above 235 becomes white, so you get crushed shadows and clipped highlights. This happens most often over HDMI, because many graphics drivers default to limited range when they detect a TV-style resolution.
- NVIDIA: Control Panel › Display › Change resolution › Output dynamic range.
- AMD: AMD Software › Settings › Display › Pixel Format (Full RGB 4:4:4 or Limited RGB).
- Intel: Intel Graphics Software › Display › Quantization Range (older systems: Graphics Command Center › Display › General).
- Monitor or TV: look for HDMI Black Level, RGB Range, or Black Level set to Low/High or Limited/Full.
- Consoles: PlayStation’s RGB Range and Xbox’s PC RGB versus Standard color space setting.
White clipping
Clipping at the bright end usually comes from a contrast setting that is too high, an over-aggressive dynamic contrast mode, or the full-to-limited mismatch above. Lower the contrast control until the brightest steps separate again, then check that white still looks clean and not gray.
What contrast ratio means
Contrast ratio is the luminance of white divided by the luminance of black. LCD panels cannot fully block their backlight, so black is never zero. OLED pixels switch off completely, so their black level is effectively zero in a dark room. Local dimming on Mini-LED displays raises the effective contrast by dimming the backlight behind dark areas.
| Panel type | Typical native contrast | Black level in a dark room |
|---|---|---|
| IPS LCD | around 1,000:1 | Dark gray, often with glow in the corners |
| VA LCD | around 3,000:1 or more | Deeper, can look uneven off-axis |
| TN LCD | around 1,000:1 | Gray, shifts strongly with angle |
| Mini-LED (local dimming) | much higher, depends on zones | Deep, with possible blooming |
| OLED | effectively infinite | True black |
Common questions
- Which of the near-black steps should I be able to see?
- On a correctly set display in a dim room, you should be able to separate most of the darkest steps from pure black. In a bright room, reflections hide the darkest steps on any screen, so test in the lighting you normally use.
- Should I raise brightness to see shadow detail?
- Only if blacks are crushed. On TVs, the Brightness control usually sets the black level, and raising it too far turns blacks gray. On most PC monitors, Brightness controls the backlight and changes the whole image.
- Why does my screen look washed out only over HDMI?
- That is the classic sign of a limited-range signal shown as full range. Set the graphics driver to full range, or set the display to expect limited range, so that both sides match.