ambientlight

Ambient light is the general, surrounding illumination in an environment, originating from all sources other than a single, intended light source. It includes daylight filtered through windows, reflections from walls and objects, and diffuse artificial lighting that fills a space. Ambient light provides baseline visibility, shapes mood, and influences how other light sources in a scene are perceived. It is often non-directional and softer than direct light.

In lighting practice, ambient light is described by luminance and illuminance. Illuminance, measured in lux or foot-candles, describes how much light falls on a surface, while luminance describes the perceived brightness of that surface. Color temperature and color rendering impact how ambient light renders colors, with cool light tending toward bluish tones and warm light toward yellowish tones. Designers aim to achieve comfortable levels of ambient illumination while minimizing glare.

In photography and film, ambient light forms the base exposure, with additional lighting added as needed. Photographers may meter for ambient brightness to preserve a natural look or adjust white balance to match the light source. Architectural and interior design use daylighting strategies, such as windows, skylights, and light shelves, to increase ambient light while reducing energy use.

Technology and ecology: Many devices include ambient light sensors to adjust screen brightness or enable automatic lighting control in spaces. In ecological contexts, ambient light cycles guide rhythms of plants and animals, and phenomena like twilight, dawn, and skyglow influence nocturnal behavior and ecosystems.