HDR (High Dynamic Range) has become an important selling point for mid-to-high-end monitors and TVs, but many users don't know how to verify whether their device's HDR performance meets the standard after purchase. Some monitors claim HDR support, yet during actual viewing, the picture appears washed out, highlights are blown out, or shadows lose all detail. This is often related to HDR settings, signal transmission, or panel quality. This article will start with the basic concept of HDR, introduce the differences between mainstream formats such as HDR10 and Dolby Vision, and teach you how to use HDR test videos and images to check your display's brightness, contrast, and color performance, helping you truly unleash the advantages of HDR visuals.

1. What is HDR? How Does It Differ from SDR?

HDR stands for High Dynamic Range, and its core purpose is to allow the picture to simultaneously retain brighter highlights and more shadow detail. Traditional SDR (Standard Dynamic Range) content typically covers a brightness range of only about 0.05-100 nits, and the color space is limited to BT.709. As a result, in high-contrast scenes, highlights either blow out into pure white or shadows lose detail and become pure black. HDR extends the brightness range to 0.005-1000 nits or even higher, while also pairing it with a wider color gamut (such as DCI-P3 and BT.2020) and higher bit depth (10-bit/12-bit), resulting in richer image layers and more true-to-life colors.

  • Wider brightness range:HDR can present a complete transition from extremely dark to extremely bright, with highlights that aren't harsh and shadows that aren't muddy.
  • Richer colors:HDR content is typically produced based on the DCI-P3 or BT.2020 color gamut, capable of displaying more colors.
  • Finer gradations:10-bit/12-bit color depth reduces banding, making gradients in skies, skin tones, and other areas smoother.

2. Common HDR Formats and Their Differences

There are currently four mainstream HDR formats: HDR10, HDR10+, Dolby Vision, and HLG. Their core differences lie in metadata type, color depth, and licensing.

  • HDR10:The most universal HDR format, using static metadata, meaning the entire film uses the same set of brightness parameters. Supports 10-bit color depth and is compatible with virtually all HDR devices.
  • HDR10+:Adds dynamic metadata on top of HDR10, allowing brightness and color to be optimized per scene or even per frame. The result is better than HDR10, but content is relatively scarce.
  • Dolby Vision:Developed by Dolby Laboratories, uses dynamic metadata and supports up to 12-bit color depth. It offers the highest picture quality ceiling but requires licensing fees from device manufacturers and content providers, resulting in slightly lower compatibility than HDR10.
  • HLG (Hybrid Log-Gamma):Primarily used for broadcast television and live streaming. Its biggest advantage is backward compatibility with SDR devices — it doesn't require metadata to display properly on regular TVs.

For average users, paying attention to whether a monitor supports HDR10 or Dolby Vision is sufficient when making a purchase, but what matters more is the actual panel brightness and contrast performance rather than just looking at certification badges.

3. Why Is Dedicated HDR Testing Necessary?

A display's HDR performance can't be judged solely by spec sheets. Many entry-level HDR monitors only pass HDR400 certification, with actual peak brightness of only around 400 nits and no local dimming, making the HDR picture barely different from SDR. Through HDR test videos and images, you can intuitively check whether the display truly extends the dynamic range after HDR is enabled, and whether there are color shifts, grayscale banding, or highlight clipping issues. Online screen testing tools provide a more convenient method for initial assessment, suitable for quickly verifying whether HDR mode is properly activated.

4. Key Metrics to Focus on in HDR Testing

  • Peak brightness:The maximum brightness the display can consistently output in HDR mode — whether highlight scenes are bright enough without appearing washed out.
  • Black level and contrast:Whether shadows can sink deep while retaining detail; insufficient contrast leads to a flat-looking image.
  • Color gamut coverage:Whether the display can correctly reproduce saturated colors in the DCI-P3 or BT.2020 color space, especially reds and greens.
  • Color gradient smoothness:Whether gradient areas such as skies and lights show obvious banding or discontinuities.
  • EOTF curve:Whether the Electro-Optical Transfer Function conforms to standards, affecting the accuracy of overall brightness mapping.

5. How to Use HDR Test Videos and Images to Verify Your Display

Before conducting HDR testing, you need to ensure that the system, display, and player all have HDR properly enabled on all three fronts; otherwise, the test results will be inaccurate. The specific steps are as follows:

  • System settings:In Windows display settings, turn on "Use HDR." In macOS, enable "High Dynamic Range."
  • Monitor OSD:Switch the display's picture mode to HDR or Cinema HDR, and turn off additional processing such as "Dynamic Contrast."
  • Signal connection:Use HDMI 2.0 or DisplayPort 1.4 or higher cables to ensure sufficient bandwidth for HDR signal transmission.
  • Player settings:When playing local HDR videos, use an HDR-capable player (such as mpv or PotPlayer) and enable hardware decoding.

Once ready, open the HDR test video and focus on observing the following frames:

  • Black level test:Transition bars from pure black to dark gray — each level should be distinguishable, not all blending together into one mass.
  • White level test:Whether details in bright areas such as clouds and lights are preserved, or whether they clip into pure white.
  • Color transition test:Gradient bars of red, green, and blue — check for banding or color shifts.
  • Highlight and shadow detail:In backlit scenes, whether both shadow hair detail and bright sky detail remain visible simultaneously.

If conditions are limited, you can also use the HDR test module in online screen testing pages. These tools typically display a set of color blocks and gradient images ranging from dark to bright. In HDR mode, observe the separation of color blocks and brightness levels to get an initial assessment of the display's HDR performance. During testing, keep ambient lighting moderate to avoid reflections interfering with the results.

6. Common Issues and Optimization Tips

  • Washed-out picture after enabling HDR:Usually caused by signal range mismatch or the display not properly entering HDR mode. Check HDR settings in both the system and display, and set the output dynamic range to "Full."
  • Blown-out highlights or crushed shadows:Try adjusting the display's HDR brightness/contrast, or turn off "Dynamic Tone Mapping" to bring the picture closer to the original signal.
  • Visible banding:May be due to insufficient color depth or excessive video compression. Using 10-bit output and high-quality source material can improve this.
  • Washed-out colors:Confirm that the color gamut settings are correct. Some displays restrict the color gamut in HDR mode — try switching to "Native" or "Auto."
  • Insufficient cable bandwidth:Replace with certified HDMI 2.1 or DP 1.4 cables to avoid HDR signal degradation due to insufficient bandwidth.

7. Summary

HDR is not simply "brighter" — it's about a wider dynamic range, richer colors, and more true-to-life image depth. Through HDR test videos and images, you can intuitively determine whether your display truly leverages the advantages of HDR, rather than being stuck at the numbers on a spec sheet. Online screen testing tools can serve as a supplementary means for quick daily verification, helping you identify setup issues and optimize display performance. Once you master these methods, whether watching movies or playing games, you'll enjoy a more immersive visual experience.