Black crush
Several requested tones merge with black, hiding intended shadow separation. Output range, content mastering, gamma/EOTF behavior, display settings, and panel processing can all contribute; the pattern alone does not isolate the cause.
Inspect the first tones above black
Near-Black Screen Test
The near-black test concentrates on very low neutral source values. Use individual 0%, 0.5%, 1%, 2%, 3%, 4%, and 5% fields, then compare the dark ramp and patch grid. The goal is to observe black crush, raised blacks, banding, mura, and low-grey uniformity—not to measure black luminance or declare an exact calibration threshold.
Three passes answer different questions
Use the near-black test for detail, position, then transition
- Prepare a realistic dark-viewing setup. Reduce direct reflections and use the display mode you normally select for dark content. Keep brightness and black-level settings documented so later comparisons use the same configuration.
- Compare full fields from black upward. Start at black, then switch one step at a time. Note the first field that looks distinct without moving closer than your normal viewing position. Do not convert that observation into a measured luminance value.
- Open the patch grid with labels on. The same low codes appear at several positions. Look for vertical bands, blotches, tint, sparkling, or areas that emerge at a different apparent level. Toggle labels off before judging subtle uniformity.
- Inspect the 5–10% ramp. A smooth source transition can show visible contouring or abrupt changes. Compression is absent from this generated ramp, but the browser and display pipeline can still alter its appearance.
- Repeat only useful comparisons. Change viewing angle separately from display settings. If the effect moves or changes strongly with angle, record that behavior rather than treating it as a fixed map of the panel.
Name what you see
Common near-black observations
Raised blacks
The black reference looks visibly luminous or grey. A backlit LCD cannot turn each pixel emitter off because it uses a backlight, while local dimming and room reflections can change the apparent black level.
Bands and mura
Low grey may expose vertical structure, clouds, tint, or other non-uniformity. On OLED, near-black drive behavior can make these patterns more apparent; a single field cannot establish severity during normal content.
Position effects
LCD glow and viewing-angle behavior can change as your head moves. Compare from a centered, normal distance before using the crosshair or grid to record a stable region.
Panel technology matters
OLED and LCD can show different dark-field behavior
OLED pixels are self-emissive, so a requested black pixel can be driven differently from a low-grey pixel without an always-on panel backlight. Near black can expose vertical banding, mura, tint, or temporal behavior, but the web page does not know the compensation state, drive algorithm, or actual emitted light.
LCD pixels modulate a shared or zone-controlled backlight. A black field may therefore reveal glow, leakage, local-dimming transitions, or a broadly lifted black floor. Use theadjustable black-level patterns for focused step comparisons and the dedicated backlight workflow only when the display is actually backlit.