变焦距物镜作为光学成象系统,是PCA—100图象彩色分析仪中的一个重要组成部分。通过变焦距物镜,将被分析图象胶片上的黑白图象成象在一支高灵敏度的摄象管靶面上。当分析者要分析大小不同的图象胶片,或者对于同一图象胶片要分析全部图象或其中某一局部图象时,操作变焦距物镜就可以方便而可靠地使被分析图象清晰地放大,在变倍过程中,变焦距物镜的象面保 Zoom objective as an optical imaging system, PCA-100 image color analyzer is an important part. By zooming the objective lens, the black-and-white image on the film being analyzed is imaged on a highly sensitive tube target. When an analyst wants to analyze image films of different sizes or if the entire image or one of the partial images is to be analyzed for the same image film, operating the zoom objective conveniently and reliably causes the image to be analyzed to be clearly enlarged In the zooming process, the focal length of the objective lens is secured