A camera has an infrared (IR) imaging subsystem that includes an IR detector. The camera also has a visual imaging subsystem for generating a visual image of an observed scene. The camera also has one or more distance measuring devices for obtaining distance related information regarding a distance from the camera to the scene and a processor arranged to receive distance related information from one or more distance measuring devices and process the received distance related information, wherein said processing comprises determining a distance to the scene based on the received distance related information. The IR imaging subsystem may also include an IR optical element for focusing IR radiation on the IR detector. The IR optical element may be operable to focus the IR radiation on the IR detector based on the determined distance.