Abstract: The disclosed embodiments relate to illumination associated with a weapon. In one embodiment, a lighting device for mounting on a weapon comprises a light source, an inertial sensor, and a controller. The light source can be used to illuminate a portion of a target. The inertial sensor can be used for sensing the forces acting on the lighting device. The controller can be configured to activate the light source when the lighting device is in a firing position for more than a first predetermined time period, and deactivate the light source when the lighting device is in a non-firing position for more than a second predetermined time period.