ScreenCheckv1.0
REFERENCE PATTERNhdr
2–3 min
Client-Side Local

HDR Reference Pattern

Original ScreenCheck HDR reference chart featuring dark shadow steps, mid-tone grays, highlight step ramps, saturated wide-gamut wedges, and geometric references.

Technical Scope & Limitations

Labeled clearly according to browser pipeline capability. If HDR signal is unconfirmed, renders in SDR reference mode without fabricated nit claims.

Browser rendering output can be influenced by OS display scaling, GPU driver color settings, and active HDR profiles.

Testing Instructions
  1. Check the top status banner to verify whether HDR rendering or SDR reference fallback is active.
  2. Examine the near-black step ramp at the lower-left for distinct dark steps.
  3. Examine the highlight step ramp at the upper-right for visible steps up to peak white.
  4. Inspect the color ramps for smooth gradation without harsh banding or clipping.
Interaction Controls
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True HDR output could not be verified — Reference pattern mode

What This Test Checks

  • Simultaneous near-black shadow steps and peak highlight wedges.
  • 16-step grayscale ramp neutrality across dark, mid, and bright tones.
  • Saturated primary and secondary wide-gamut color wedges.
  • Aspect ratio and geometric centering markers.

How to Perform the Test

  • Verify that your browser environment signal is detected or active in the top banner.
  • Enter fullscreen mode to view the chart edge-to-edge.
  • Check the lower-left near-black boxes (0 to 16) for clear step differentiation.
  • Check the upper-right highlight boxes (240 to 255) for visible specular step separation.

What to Look For

  • Smooth step gradations without harsh banding, color tint shifts, or crushed black borders.

Common Display Problems & Diagnostic Guidance

SDR Fallback vs True HDR Rendering

If the browser does not support high dynamic range media queries or if OS HDR is disabled, the chart renders gracefully in standard sRGB reference mode.

Frequently Asked Questions

Does this chart assign physical nit values to white boxes?

No. ScreenCheck adheres strictly to technical honesty. CSS colors represent digital encodings; physical luminance in nits depends entirely on monitor hardware peak capability and active tone-mapping.