Zoom lens barrel for macrophotographing

摘要

A two-lens group type zoom lens having a high magnification factor and simple structure yet having smooth transfer between normal zooming and macrophotographing positions. The positions of the first and second lens groups are defined by a respective zooming cam slot and lead slot formed in a cam sleeve. For focusing, a focusing operation sleeve is rotated to determine the position of the first lens group along the optical axis. A linear slot is provided extending from a telephoto end position of the zooming cam slot parallel to the optical axis direction of the lens. Additional circumferential slots may be provided extending from the zooming cam slot and lead slot and a click-stop mechanism utilized to stop the zooming operation sleeve at the telephoto end position and macrophotographing range position.