Patent attributes
A compact high performance objective zoom lens system is disclosed that provides optimum optical performance over the entire zoom focal length range at focus distances from close to infinity. The system comprises, from object space to image space, one focusing objective lens group (comprising a focus lens group and a stationary lens group) and three zoom lens groups aligned on the optical axis. The focus lens group and the zoom lens groups are axially movable along the optical axis for focusing and zooming. In one embodiment, the system has a focal length zoom region from about 19 mm to 90 mm, an aperture of F/2.7 and substantially the same optical performance as high quality fixed objective lenses of the same range. The performance characteristics of this system makes it suitable for use with both film and electronic detector cameras.