| 摘要 |
PURPOSE:To measure easily a transfer function (MTF) at the various angle of field of each kind of lens, by arranging another photodetecting element having a wide linear range of a sensitivity characteristic curve in the neighborhood of a solid scanning element and adjusting the intensity of illuminating light by its output. CONSTITUTION:A slit 2 provided on the surface of a body of a lens 1 to be inspected is illuminated by an illuminating apparatus and a light enlarged and projected by the lens 1 is formed an image on a solid scannining element 3 for MTF measurement such as a CCD etc. The slit 2 and the CCD3 are provided plurally adjusting to each picture size and an opening 4 is provided near one set at least among a set of the splits corresponding to each image height and then, the opening 4 is irradiated by the same illuminating apparatus to that of the slit 2. The second photodetecting element 5 having a wide range of linearity of a sensitivity characteristic such as silicon-cell etc., is arranged at the position of the image by the lens 1 of this opening 4. |
