摘要 |
A method and lens system for modifying the modulation transfer function of the light passing through the lens system to a camera or other imaging system that includes providing a spatial frequency response modifying (SFRM) filter within the lens system. The SFRM filter may be a thin film(s) or other type of modifying filter, including any conventional diffusion filters. The SFRM filter is located along the optical axis where the on-axis, zero field angle light rays are collimated in any lens system and form light beam(s) of a substantially constant cross sectional area throughout the range of focusing of a prime objective lens or throughout the ranges of zooming and focusing of an objective zoom lens for providing a consistent modulation transfer function of the light reaching the camera or other imaging system. <IMAGE> |