照相物镜传递函数和主观评价因子的测定

我们利用CCD扫描位于被测照相物镜前面的平行光管焦平面上的狭缝像,采样数据通过A/D变换后输入计算机,把这些数据进行快速傅立叶变换即可求出被测照相物镜的OTF值;同样我们用CCD采样对数光栅目标物通过被测照相物镜后处于平行光管焦面上的像,由于被测照相物镜的SQF可以表示为极坐标形式下系统OTF关于对数空间频率的积分,它由采样得到的目标光栅像各个峰值归一后与各自相邻对数频率间隔的乘积累加得出。

The Measurement of the OTF and SQF of the Photographic Lenses

We measured the OTF of a photographic lens by digital Fourier Transform,using a CCD to scan the slit image in the focal plane of the collimator in front of the measured lens.The Fourier Transform of the sampled data of the image,after input into the computer through a A/D converter,gave the OTF value. We measured the SQF of the lens using CCD to sample the logarithmic grating image fozmed by the measured lens and obta-ined the SQF from the integration of the system OTF expressed in polar coordinate and logrithmic frequency coordinate.