OLED Black Crush & Shadow Detail Test

Black crush occurs when an OLED display fails to illuminate subpixels at low digital signal levels (such as RGB 1 to RGB 5 in an 8-bit signal). Because organic OLED subpixels require a minimum threshold voltage to turn on, poorly calibrated display drivers or aggressive energy-saving algorithms crush these dark gray values into total pitch black.

In a pitch-black room with your display set to fullscreen, look at the 16 calibration blocks. If blocks 1, 2, or 3 are completely invisible and blend indistinguishably into the background, your screen is crushing black. In a well-calibrated display, block 1 should be barely perceptible, and block 2 should be clearly distinct from absolute black.

To mitigate black crush: (1) Ensure you are in a dark room; (2) Adjust your display’s Brightness or Black Level control by 1–2 points; (3) Change your Gamma setting from 2.4/BT.1886 to Gamma 2.2 or sRGB; (4) Disable auto-energy saving or ambient light sensors; (5) Fine-tune the low-end white balance (2% or 2.5% code value offset) in your display menu.

Gamma 2.2 follows a strict power function suitable for general PC lighting. sRGB lifts the lowest gray values slightly using a linear baseline, making dark details easier to see in ambient light. BT.1886 is the professional mastering standard for dark cinema environments; on zero-black OLEDs, BT.1886 matches Gamma 2.4, requiring darkroom conditions for proper shadow detail visibility.

The dynamic flashing target tests subpixel temporal response delay (dark smearing). Organic OLED pixels resting at absolute 0V can take a few milliseconds to ignite when moving. The 1Hz–4Hz pulse allows you to verify whether subpixels light up instantly without smearing or flickering when waking from pitch black.

Raising display brightness too much will elevate RGB level 0 above absolute black, turning true OLED pitch-black into a glowing, washed-out dark gray. The goal is to raise near-black code values (RGB 1+) while keeping RGB 0 strictly unlit at 0.0000 nits.

WOLED displays use a white subpixel alongside RGB filters to boost brightness, which can sometimes cause color tint shifts or slight crush near 1% gray. QD-OLED displays use pure quantum-dot color converters with direct RGB emitters, maintaining exceptionally clean color purity and faster subpixel wake-up times near black.

Black crush is almost always a calibration or picture mode configuration issue, not a permanent hardware defect. It can be corrected using TV picture settings, GPU color management controls (NVIDIA Control Panel / AMD Software), or color calibration LUTs.

Yes. HDR content uses the PQ (Perceptual Quantizer / ST.2084) EOTF curve instead of traditional gamma. In HDR10 and Dolby Vision, code value 1 represents an exact luminance target (e.g., 0.0001 nits). Display tone-mapping engines must accurately translate these low PQ targets without clipping dark scenes.

Yes. The test uses standard 8-bit RGB color patterns rendered via browser canvas. It applies no abnormal electrical stress to your panel and runs entirely client-side without collecting any personal data.