shutter

Shutter refers to a device that temporarily blocks or limits the passage of light or visibility. It is used in architecture, optics, and photography to control exposure, privacy, and protection from the elements, and in other instruments to regulate timing and light.

Window shutters are coverings installed over openings such as windows. They can be hinged, sliding, or rolling, and come in materials including wood, vinyl, aluminum, and composites. Slatted or louvered shutters permit adjustable light and ventilation, while solid shutters provide privacy and weather protection. Modern shutters often include motors and can be integrated with smart home systems for remote control, energy efficiency, and security.

In cameras, the shutter is the mechanism that opens to expose the image sensor or film and then closes to end the exposure. The two primary designs are leaf shutters, typically located within the lens or behind the ap-erture, and focal-plane shutters, housed in the camera body. The term shutter speed describes how long the shutter remains open. Modern cameras may use electronic shutters, rolling shutters that read the sensor line by line, or global shutters that expose all pixels simultaneously. Shutter design influences exposure duration, motion blur, flash synchronization, and the potential for mechanical wear or electronic artifacts.

Beyond photography, shutters appear in other optical devices and in architectural contexts as described, serving to block or regulate light or visibility as needed. Across applications, shutters balance light control, timing, and protection within their respective systems.