Feature

Wide-range TV Zoom Lens

J. Brian Caldwell

Zoom lenses for T V cameras are required to have a large zoom range while maintaining high image quality at a large aperture. These requirements are similar to those for consumer video camera objectives, although the latter tend to sacrifice image quality to attain compactness and low-cost. Since cost, size, and weight are less important than image quality and zoom range, TV zooms can be substantially larger and often incorporate one or more abnormal dispersion glass elements to reduce secondary color.