What is HDR400?
HDR400 refers to the VESA DisplayHDR 400 tier, the entry level of HDR certification. What it means, what it does not, and how True Black 400 differs.
HDR400 usually refers to VESA DisplayHDR 400, the entry tier of the DisplayHDR certification, which requires a monitor to reach a peak brightness of 400 cd/m² along with baseline requirements for colour and bit depth. It indicates that a display can accept and show HDR content, with a modest step up in highlight brightness over standard displays.
What HDR400 tells you
- The display accepts HDR signals, such as HDR10.
- It reaches a defined peak brightness for highlights.
- It meets baseline requirements for colour gamut and processing.
What it does not tell you
Plain HDR400 sets relatively light requirements for black level. On an LCD, HDR400 HDR is a modest step up rather than a dramatic one. Higher tiers, such as DisplayHDR 600 and 1000, require more brightness and stronger dimming.
True Black 400 is different
DisplayHDR True Black 400 is a separate tier designed for OLED displays. It also targets 400 cd/m² peaks, but adds very strict black-level requirements. Because OLED pixels switch fully off, a True Black display can make HDR look dramatic at the same peak brightness, especially in a dim room. Alter Ego Nocturne 49 is certified DisplayHDR True Black 400.
On Alter Ego displays
- Nocturne 49: DisplayHDR True Black 400.
- Solitaire 27 and Horizon 49 Noir: HDR400, as specified.
- Atelier 40 and Horizon 49 Blanc: HDR, meaning they accept HDR signals; no tier is stated.
