Lens assembly with switched ultra-narrow field-of-view configuration

摘要

A lens assembly includes a housing defining an interior volume having a substantially linear optical axis extending therethrough. A zoom group is disposed in the housing in an optical path segment on the optical path between a first lens and an aperture mechanism. The zoom group is movable between a plurality of field-of-view (FOV) positions along the optical path segment. An ultra-narrow field-of-view (UNFOV) lens group is movable between a first UNFOV position outside the optical path and a second UNFOV position in the optical path segment. The lens assembly has a plurality of FOV configurations with the UNFOV lens group in the first UNFOV position, and a UNFOV configuration with the UNFOV lens group in the second UNFOV position. The lens assembly accommodates a number of different FOVs within a limited volume with a small number of lenses, and without folding or otherwise redirecting the optical path.