Active daylighting is a system of collecting sunlight using a mechanical device to increase the efficiency of light collection. Active daylighting systems are different from passive daylighting systems in that passive systems are stationary and do not actively follow the sun. 
Types of active daylighting control systems
There are two types of active daylighting control systems: closed loop solar tracking and open loop solar tracking systems.
Closed loop systems track the sun by Relying was set of lens or sensors with a limited field of view, directed at the sun, and are fully illuminated by sunlight at all times. As the sun moves, it starts with one or more sensors, which the system detect and activates motors or actuators to move the device back to a position where all sensors are once again. 
Open loop systems track the sun through the sensors (may be used for calibration). These systems typically employ electronic logic which controls devices motors or actuators to follow the sun based on a mathematical formula. This formula is typically a pre-programmed sun path chart, detailing where the sun will be at a given latitude and a given date and time for each day.
Companies or products that use active daylighting systems
- Solatube Daylighting Systems 
- Himawari Daylight Collector
- Sunflower Corporation
- Ciralight SunTrackers 
- Natural Lighting Co.Int.
- SunCentral Inc.
- Parans Solar Lighting
- Solar tracker
- Daylight factor
- Passive daylighting
- Jump up^ Active Daylighting ArchivedFebruary 2, 2010, at theWayback Machine. retrieved 9 February 2009
- Jump up^ A new strategy for EUCLIDES subdegree solar tracking