LED Display Brightness
The brightness of an LED display affects the visibility of content. There are many concepts relating to brightness, such as nits and lumens. In this guide, we will discuss some of these concepts.
In general, brightness plays a crucial and decisive role among a number of optical factors, such as contrast ratio, grayscale, and colour saturation, because only when the screen is sufficiently bright can the other optical parameters be detected. The installation position, orientation, and surrounding environment all have a significant impact on the brightness of outdoor LED displays.
Lumens & Nits
When the display is operating regularly, the light intensity per square metre is measured in cd/m2 or nit(s). It is obvious that the display will be brighter the higher the setting. The typical brightness needs for indoor and outdoor displays are summarized in the table below.
| Location | Condition | Nits |
| Indoor | Shadow | 800-1500 |
| Indoor | Direct sunlight | 1500-2500 |
| Outdoor | Shadow | 2500-4000 |
| Outdoor | Sunset | 4000-5500 |
| Outdoor | Direct sunlight | 5500+ |
Lumen, on the other hand, is the amount of light emitted by a single candle a foot away. One nit contains many lumens.
Outdoor Brightness Conditions
LED display brightness for an outdoor screen has to be strong enough to compete against sunlight in various conditions. Outdoor LED brightness levels are: shadow, sunset, and extreme (direct sunlight). Outdoor screens should be bright enough to be readable and vivid for the viewers.
The brightness can be higher at around 5500 nits when the outdoor LED display is facing north since the sunlight will be more direct. Alternatively, if the outdoor LED video wall is in a city where tall buildings or trees provide shade, the brightness can be around 4000 nits.
The season can also change brightness requirements—in the summer, the screens need to be brighter than in the winter, since there are more sun hours.
LED Display Brightness by Application
The applied brightness of an LED screen may vary as a result of the many unique usage and installation locations in real applications. For instance, an LED screen for document presentation does not have to be as bright as the screen with advertising content or video playback.
It is also recommended not to design the LED screen with too much brightness for its indoor application and location, as overly bright displays can hurt the viewers’ eyes. The brightness of an LED display will differ if it is for a shopping mall or a conference room, and the brightness needed is related to the size of the conference room. For outdoor applications, the brightness can be automatically adjusted according to the brightness of the light after adding light sensor to achieve the most suitable brightness for viewer.
Changing LED Display Brightness
There are two main methods of changing the display brightness: change current and modulate pulse width. In addition to LED’s saturation, the brightness of other LEDs is essentially proportional to the amount of current flowing.
Another technique uses a high refresh rate to combat grayscale by changing the optical pulse width, or duty ratio, on a regular basis. Almost all LED displays employ pulse width modulation to adjust grey levels because it is more suited to digital control and is used widely nowadays by microcomputers to generate content for LED displays.
LED Display Brightness FAQ
Outdoor LED video walls can have a brightness of up to 8,000-10,000 nits, while indoor LED signage have a brightness range of 800 to 1,500 nits.
The perceived intensity of screen light is known as brightness.
LED lights can dim due to, low-quality light bead boards, inadequate heat dissipation, and other external variables.
It is best to have a LED display luminance of over 5000 nits.