The purpose of this project has been to study possible lens designs for use with the 19 to 1 reduction Minlcard system. Based on the concept that the Minlcard process would be used to reduce aerial photographs with limiting resolutions of around 40 lines/mm, a lens would therefore have to be capable of resolving around 764 lines/am. This would require a point source image of around 2 /u, or practically a diffraction limited lens for an aperture of f/2.nSeveral types of designs were considered, and two types of lenses were completely designed. These were a curved field design and an inverted telephoto design. A sample of the latter design was made up and tested photographically. The results were close to those predicted from the design data, and showed that this type of lens may suffice for some of the proposed applications.
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