bSchool of Remote Sensing and Information Engineering,Wuhan University,129 Luoyu Road,Wuhan,China,430079)

With the rapid development of three-dimensional (3D) modelling, camera calibration is paid more and more attention. In this article, we analyse the influence factors in the calibration: the camera and lens, the shape of control points, photography model and the scale between calibration object and measurement. Appropriate model can get the right result quickly, and the position of the model in the image effects the calibration result directly. The control points should cover the whole image evenly. The cross control point is better than circle points. The more similar the size of object model and the measurement object, the higher precision the calibration has. Actually, each of them plays an important part in calibration. We can get higher precision result based on considering those influence factors. And the experiments in the end show that the work is worthy. It means that we should take those factors into account