Zoom lens with jointly and separately adjustable systems - has mechanism enabling separate adjustment only in limit position

摘要

The lens has two axially movable lens systems with an adjusting mechanism for simultaneous adjustment of both systems or of one system independently of the other for close-up focusing. A releasable coupling is provided between a manual adjusting member (14) for one lens system and an adjusting member (15) for the other lens system. The coupling has a movable element which couples the two adjusting members for joint adjustment. A lock operated by a further moving part of the coupling disengages the adjusting members from each other only in a given limit position, pref. representing max. focal length.