The Minox BL is an improved version of the Minox B, the most notable improvement being the replacement of the previous selenium cell meter with a CdS light meter. The BL had a very short production run, lasting only two years from 1972 to 1973, but it is still highly considered by Minox users. In addition to having a more modern and reliable light meter, the Minox BL also has the film advance-shutter set mechanism of the Minox C. The earlier models of Minox cameras advanced the film when the camera was slid shut, whether an exposure had been made or not. The Minox C famously modified this mechanism to allow the camera to be closed without advancing the frame, in the event that no exposure was made - the BL also incorporates this feature. Unlike the C, and just like the B, while the camera's meter requires a battery for power, the rest of the camera is entirely mechanical and can operate without a battery. The BL also added an improved lens over the B and can use all the same accessories.