| 摘要 |
PURPOSE:To prevent a flash device from emitting light unnecessarily by preventing the flash device which provides almost no lighting effect in a long focal length state from being elevated for use when an optical photography system is set to long focal length. CONSTITUTION:A short and a long focal length state are shown in the figure. When the short focal length state is switched to the long focal length state, the sub lens 15 of an extender 14 moves off an optical path of photography to leave only a main lens 12 on the optical path of photograph and in said long focal length state, a lens barrel part 30 is moved to in front of a camera by the cover 32 of the lens barrel part 30. The extender 14 is energized to rotate clockwise when viewed from in front of the camera associatively with the forward movement of the lens barrel 30, and rotated counterclockwise by a cam following- up means to set the sub lens 15 on an optical axis of photography, setting the long focal length state by the main lens 12 and sub lens 15. |
