As electronic products become more and more advanced, users will pay attention to the interactionDisplayOne of the most critical parameters of visual parameters is brightness (unit: nits). The impact of brightness on the experience mainly depends on the brightness and color in the usage environment. Generally speaking, the usage environment can be divided into indoor and outdoor, and the requirements for brightness in these two scenes are significantly different. Therefore, we must first understand the brightness unit in the brightness parameter.
1. Candela (cd) – Brightness of a single point light source
- Definition: Describes the intensity of light emitted by a light source in a certain direction.
- Unit type: Light intensity units (luminous flux ÷ spatial angle).
- Usage scenarios: directional brightness of laser pointers, flashlights, and LED backlights.
- Explanation example: The light intensity of a standard candle is approximately 1 candela, unit cd.
2. Nit (Nit = cd/m²) – Brightness per unit area
- Definition: Describes the brightness of light emitted per square meter by a display or surface.
- Unit type: Brightness unit cd/m² (candela/area). Mobile phone screen: 400~1000 nits
- scenes to be used:TFT LCD displayA common unit of brightness for TV screens, mobile phone screens, and monitors. Mobile phone screens: 400-1000 nits
3. Lumen (lm) – the total output of all luminous energy
- Definition: Describes the total luminous flux emitted by a light source per second (regardless of direction, the larger the brighter).
- Unit Type: Total output of light (total luminous output for the entire space).
- Usage scenario: total brightness of LED bulbs and projectors.
| Brightness Unit | Description | Remarks |
| Lumen (lm) | The total brightness of all light sources | |
| Candela (cd) | Brightness in a certain direction | |
| nits | The brightness of light scattered per square meter | Brightness per unit area (for display screens) |
4. Overall
LCDBrightness of the display: nits
LED brightness test: Candela (cd)
Projection/lighting effect: Lumen (lm)
