Perkin-Elmer It turned out that Perkin-Elmer, which was probably the best optical manufacturer in America at that time, had built the primary mirror for this telescope.
结果事实是，当时美国最优秀的,光学部件制造商，为这个望远镜制造主镜。
2
This is the distance (usually in mm.) from the lens (or primary mirror) to the point where the telescope is in focus (focal point).
就是从透镜(或者主反射镜)到焦点的距离，通常单位是毫米(mm)。
3
The work on the technical transform of the mounting system of the primary mirror of the 1.2m alt-az telescope at the Yunnan Observatory is introduced and discussed in this paper.