A camera having a housing, an optical system and an electrical image sensor, particularly for applications in the exterior region of motor vehicles, limits or prevents undesirable influences from moisture penetrating the camera or the housing. This is achieved by virtue of there being channels provided for air circulation in an interior of the optical system on the basis of the heating of air in the housing by operation of the image sensor, with the channels channeling air around lenses of the optical system. The channels may be along an internal wall of a lens frame of the optical system, and the channels may extend from an end portion of the lens frame at or near the image sensor to an internal space within the lens frame and between two adjacent lens elements of the optical system.