HDR Test
Test HDR10 support, peak brightness, and wide color gamut capabilities
💡 Why This Test?
HDR (High Dynamic Range) delivers dramatically brighter highlights (400-1000+ nits), deeper blacks, and wider colors (DCI-P3 or Rec.2020) compared to SDR's limited 200-400 nits and sRGB gamut. HDR content shows more realistic lighting, vibrant colors, and visible detail in both bright and dark areas simultaneously.
This test checks if your display supports HDR10, measures subjective peak brightness, tests wide gamut coverage, and evaluates local dimming performance. True HDR requires DisplayHDR 400+ certification (400 nits minimum), 10-bit color, and ideally local dimming zones for contrast.
✅ What You'll Check:
- Peak brightness capability (SDR vs HDR)
- Color vibrancy in wide gamut mode
- Local dimming effectiveness (blooming test)
- Whether OS/browser HDR is properly enabled
📖 How to Use This Test
- Enable HDR in Windows (Settings → Display → HDR) or macOS first
- Start the fullscreen test (browser HDR support varies)
- Navigate through 5 patterns: peak white, color gamut, gradient, local dimming, blooming
- Compare brightness when HDR is on vs off
- Look for vibrant, saturated colors in gamut test
- Check for blooming halos in the local dimming tests
⚠️ Important: Web-based HDR testing is limited. Browsers have incomplete HDR support. For accurate measurements, use Windows HDR Calibration app or dedicated tools. This test is primarily subjective/comparative.
💡 Tip: DisplayHDR 400 = 400 nits, DisplayHDR 600 = 600 nits + local dimming, DisplayHDR 1000 = 1000 nits + full array local dimming. True HDR needs 10-bit color output - check GPU settings.
👀 What You Should See
🌟 Peak Brightness
🎨 Color Gamut
📊 Gradient
🌑 Local Dimming
💫 Blooming
Test peak brightness, color gamut, and local dimming. Press ESC to exit.
✨ HDR vs SDR
✅ HDR (High Dynamic Range)
- • Peak brightness: 400-1000+ nits
- • Wide color gamut (DCI-P3, Rec.2020)
- • 10-bit color depth (1.07B colors)
- • Better contrast and highlights
- • Local dimming support
📺 SDR (Standard Dynamic Range)
- • Peak brightness: 200-400 nits
- • sRGB color gamut (narrower)
- • 8-bit color depth (16.7M colors)
- • Standard contrast
- • No local dimming
📋 Testing Guidelines
🌟 Peak Brightness
Look at the brightest white. Should be very bright without washing out colors.
🎨 Color Vibrancy
Colors should look vivid and saturated, especially reds and greens.
🌑 Local Dimming
Bright objects on black background should have minimal glow/blooming.
⚡ HDR Standards
- • HDR10: 1000 nits, 10-bit, Rec.2020
- • DisplayHDR 400: 400 nits minimum
- • DisplayHDR 600: 600 nits + local dimming
- • DisplayHDR 1000: 1000 nits + local dimming
📋 How to Test
Enable HDR Mode
In Windows: Settings → Display → HDR. In macOS: System Preferences → Displays → HDR.
Start Fullscreen Test
Navigate through 5 test patterns: peak brightness, color gamut, gradient, local dimming, and blooming test.
Compare with SDR
If possible, toggle HDR on/off to see the difference in brightness and color.
Evaluate
Note the peak brightness, color vibrancy, and any local dimming artifacts (blooming).
⚠️ Important Notes
- • HDR must be enabled in OS settings first
- • Browser support varies (Chrome, Edge recommended)
- • Web-based HDR testing is limited - use OS test patterns for precise measurements
- • This test is primarily subjective/comparative
🔧 Common Issues & Solutions
💎 "HDR doesn't look impressive - same as SDR" (DisplayHDR 400 limitations)
What's happening: VESA DisplayHDR 400 entry tier - only requires 400 cd/m² peak brightness, NO local dimming zones, NO wide color gamut requirement. Essentially "SDR cranked brighter" not true HDR. Can't display deep blacks (>0.4 nits) or true highlights. HDR 400 monitors (MSI Optix MAG274QRF, Dell S2721DGF): Same ~1000:1 IPS contrast as SDR. HDR10 content mastered for 1000-4000 nits gets tone-mapped down losing highlights.
DisplayHDR tier comparison: HDR 400: 400 nits peak, 0.40 nits black, no dimming zones. HDR 600: 600 nits peak, 0.10 nits black, optional FALD. HDR 1000: 1000 nits peak, 0.05 nits black, FALD required (minimum 8 zones), DCI-P3 90%+ color. HDR 1400: 1400 nits, 0.02 nits black, 384+ zones (ASUS PA32UCG). True HDR experience needs HDR 600+ or OLED (infinite contrast, 0.0005 nits black).
✅ Solution: For real HDR: Upgrade to DisplayHDR 600 minimum (BenQ EX3210U, ASUS ROG PG27UQR) or HDR 1000 with FALD (MSI MPG321URX 1152 zones, $999). Best: OLED monitors (LG 27GR95QE, ASUS PG27AQDM) perfect blacks, 1000 nits HDR, no blooming. If stuck with HDR 400: Disable HDR for SDR content (better gamma curve), only enable for HDR10 games/movies. Set Windows "HDR brightness" to 100% and adjust in-game HDR calibration instead.
☀️ "Windows HDR makes everything blindingly bright or washed out" (SDR content in HDR mode)
What's happening: Windows HDR maps SDR content (80 nits white) to HDR range using "SDR content brightness" slider. Default 50% = 200 nits, way too bright for UI/desktop causing eye strain. Apps without HDR support (Chrome, Firefox, Office) rendered as SDR then scaled to HDR - colors look washed out (compressed to smaller gamut). Windows 10 HDR worse than Windows 11 (improved tone mapping).
HDR vs SDR white point mismatch: SDR white: 80 nits (sRGB standard). HDR white: 203 nits (100% diffuse white in HDR10). Monitor peak: 400-1000 nits (specular highlights only). Setting "SDR brightness" to 50% makes desktop 200 nits - painful in dark room. Too low (20%) makes text unreadable. Color shift: SDR sRGB content stretched to DCI-P3/BT.2020 causing oversaturation or desaturation depending on tone mapper.
✅ Solution: Windows Settings → Display → HDR → Calibrate HDR. Set "SDR content brightness" to 25-35 (not 50 default). Set "HDR content brightness" to match monitor peak (400/600/1000). Use Windows 11 for better Auto HDR and tone mapping. Enable "Use HDR" only when watching HDR content - disable for desktop work. Apps with HDR support: Edge browser, MPC-HC, VLC (with D3D11 output), native HDR games. Chrome/Firefox lack HDR = poor experience.
🌟 "Bright star in space has giant halo around it" (FALD blooming vs no dimming)
What's happening: Local dimming blooming - single bright object lights up entire dimming zone (32-384 zones typical) creating visible "halo" around highlights. Worse on cheap FALD (32 zones = huge zones), better on mini-LED (576-1152 zones = smaller halos). HDR 400 monitors NO local dimming - bright stars raise entire screen brightness, destroying blacks. Full-screen black with single white pixel: HDR 400 shows gray background (0.4 nits), FALD shows halo (~0.15 nits), OLED perfect (0.0005 nits).
Zone count vs blooming trade-off: 8-32 zones (basic FALD): Severe blooming, only useful for large bright areas. 384 zones (good): Noticeable halos on starfields, acceptable for most content. 576-1152 zones (mini-LED): Minimal halos, excellent HDR. Example: ASUS PA32UCG (1152 zones, $5000) vs Samsung Odyssey Neo G9 (2048 zones, $2500) vs OLED (33M zones = per-pixel). Algorithm matters: BenQ/EIZO conservative (less blooming, dimmer highlights) vs ASUS aggressive (brighter peaks, more bloom).
✅ Solution: If HDR 400 (no dimming): Accept limitation or upgrade - can't fix hardware. If FALD with blooming: Lower "Local Dimming" aggressiveness in OSD (High → Medium). Some monitors: "Black Insertion" or "Blooming Reduction" mode. Content-dependent: Bright UI on black = worst case, natural scenes better. Best solution: OLED (LG 27GR95QE $999, ASUS PG27AQDM $999) zero blooming, perfect blacks. Or wait for micro-LED (per-pixel dimming, no OLED burn-in risk, $5000+ when available).
🎬 "HDR content looks wrong - blown out highlights or crushed blacks"
What's happening: HDR content mastered for 1000-4000 nits displayed on 400-600 nit monitor requires tone mapping - compressing out-of-range values. Poor tone mapper: Clips 600+ nits to monitor max (details lost in bright areas) OR crushes near-blacks (shadow detail lost). Different tone mappers: Windows HDR, GPU driver (NVIDIA/AMD), game engine (Unreal/Unity), media player (MadVR, VLC). Inconsistent results across apps.
EOTF vs PQ curve issues: HDR10 uses PQ (Perceptual Quantizer) EOTF - absolute luminance encoding. 0% = 0.0001 nits, 50% = 10 nits, 75% = 100 nits, 100% = 10000 nits. Monitor can't hit 10000 nits - must remap. Static tone mapping: Simple curve, fast but loses highlight detail. Dynamic tone mapping: Analyzes scene, adjusts per frame - better quality but can cause brightness "pumping" (visible in dark scene → bright scene transitions).
✅ Solution: Calibrate in-game HDR: Most games (Cyberpunk, Horizon, COD) have HDR calibration - set "Peak Brightness" to monitor's actual spec (400/600/1000 nits). Use "HDR Paper White" 80-120 nits, "HDR Black Point" lowest visible. For video: MadVR player (best tone mapping, GPU-intensive) or mpv with libplacebo (excellent quality). Windows 11 Auto HDR better than Win10. NVIDIA drivers: "HDR Mode" → PC (not Video) for correct tone mapping. Ideal: Match content mastering to monitor (1000 nit content on 1000 nit display).
⚡ "Screen flickers or brightness jumps when enabling HDR"
What's happening: HDMI/DP signal mode switching between SDR and HDR causing black screen flicker (1-3 seconds). Windows sends HDR metadata to monitor triggering EOTF mode change. Dynamic local dimming algorithms causing visible brightness "pumping" - scene changes from dark → bright rapidly adjusting backlight. VRR (G-Sync/FreeSync) conflicts with HDR on some monitors. Cable bandwidth insufficient (HDMI 2.0 struggles with 4K 144Hz HDR).
Local dimming flicker issues: FALD zones transitioning causes visible "scanning" or "pulsing" - worse on cheap controllers with slow response. 60Hz → 120Hz update rate difference: Some panels flicker when switching refresh rates in HDR mode. Firmware bugs: Early HDR monitors (2018-2020) have buggy HDR implementation causing instability. Samsung VA panels: VRR + HDR + Local Dimming = known flicker issue (firmware update helps). Adaptive sync range matters: 48-120Hz stable, 40-144Hz may flicker.
✅ Solution: Update monitor firmware from manufacturer website (critical for HDR stability). Use DisplayPort 1.4 HBR3 (not HDMI) for 4K 144Hz HDR. Disable "Dynamic Contrast" or set Local Dimming to "Medium" instead of "High". Windows: Keep HDR always on or always off - don't auto-toggle (reduces mode switching). NVIDIA: "G-Sync Compatible" monitors may have VRR+HDR issues - try disabling VRR for HDR content. If persistent: Monitor defect or poor HDR implementation - consider RMA or upgrade to newer model (2022+ HDR monitors more stable).