用怎么样的远镜初学天文的同志们,大都喜欢追求远镜的放大倍率,五十倍,一百倍,二百倍……越大越好。其实天文观测不一定要很高的倍率,要看观测什么而定。要观测行星表面,月亮表面,以及彼此距离很近的双星等,自然是倍率越高越好;但是要观测星云、星團、变星以及光度较暗的天體,则需要大的口径而不是高的倍率了。因为放大倍率=物镜的焦距/目镜的焦距从这里,我们可看到,同一物镜,只要换用不同焦距的目镜,便可得到不同的倍率,所以,值得我们追求 The comrades who use a variety of telescope astronomical astronomy, most like to pursue the magnification of the telescope, fifty times, one hundred times, two hundred times ... the bigger the better. In fact, astronomical observations do not necessarily have to be very high, depending on what is observed. To observe the surface of the planet, the surface of the moon, and the double stars that are in close proximity to each other, it is natural that the higher the magnification, the better; but to observe the nebula, star clusters, variable stars, and dark objects, you need a large caliber instead of a high magnification. Now. Because the magnification = the focal length of the objective lens / the focal length of the eyepiece from here, we can see that the same objective lens, as long as the eyepiece with different focal lengths, can get different magnification, so it is worth our pursuit