Abstract:The telephoto lens can capture images from farther locations, but the particularity of telephoto lens imaging challenges the traditional camera calibration methods. To solve the problem, this paper presents a camera internal reference calibration method based on the parallel optical tube and two-dimensional rotating platform. The camera is mounted on a two-dimensional rotating platform to image a transmissive checkerboard placed in a parallel light tube. Rotate the 2D platform to change the position of the camera, and get a clear checkerboard image under different positions. The pixel coordinates of the checkboard points and the angle data of the 2D platform are collected to establish the appropriate model, and the internal parameters of the telephoto camera are optimized and solved. Thus, the calibration of the telephoto camera in the laboratory is realized. Compared with the actual image, the average error is about 0.5 pixels, which verifies the feasibility of the algorithm.