A Lens Measuring Method Using Photoconductive Cells
Many characteristics of a lens can be evaluated using a method based on changes in the light distribution which take place in the image plane as the image of high-contrast target is moved through focus. A photoconductive surface in the image plane measures this information in the image, without having to resort to conventional photographic techniques or the human eye. Basically, the output of the instrument indicates the degree of sharpness of image. Thus, by locating the plane of best focus by instrument very exactly, the characteristics that can be measured are: the optical distances, and variations thereof at various wavelengths, in the visible and in part of the infrared region; and particular aberrations of a lens. Indirectly, the instrument indicates the resolving ability of the lens; thus qualitative comparisons between lenses can be made with this method.
- Print ISSN
- 0361-4573
- Published
- 1965-06
- Content type
- Original Research
- DOI
- 10.5594/J08290