Abstract: A camera having a photographic optical system contained in a lens barrel including a zoom cam tube and a collapsible mount cam tube. The zoom cam tube is movable in a focal length adjustment region between a Tele position and a Wide position, while the collapsible mount cam tube is movable in a collapsible mount movement region between the Wide position and a fully collapsed position. During focal length adjustment action, a gear which transmits a drive force of a motor is in engagement with a first rack on the zoom cam tube, and only the zoom cam tube rotates. Due to this rotation, a cam portion is rotated via other gears meshed with the first rack, and a pair of viewfinder lenses and a light generating unit, are made movable. During collapsible mount action, the gear is in engagement with a second rack, only the collapsible mount cam tube is rotated, and the drive force of the motor is not transmitted to the cam portion.