Photographic lens with variable range focus adjustment between selected end limits

摘要

A photographic lens including a focus ring rotatable about a lens housing between prescribed end limits to displace a focusing lens element between positions corresponding respectively with relatively long and relatively short focus settings, wherein a range stop assembly is provided for selectively adjusting the end limits at focus settings corresponding with positions at which scenes or events are anticipated by the photographer. In a preferred form, the range stop assembly comprises a pair of axially slidable adjustment sleeves normally biased into locked positions for rotation with the focus ring and respectively supporting control pins extending into cam grooves on a fixed portion of the lens housing to define the end limits of focus ring rotation. Each adjustment sleeve is movable manually from the locked position to permit rotation relative to the focus ring thereby altering the relative position of the associated control pin within its cam groove to adjust the corresponding end limit of focus ring rotation.