Those telescopes that do not employ reflection use refraction. They have a system of lenses, an idea first used to look at the stars by Galileo.

那些不利用反射的望远镜利用的是折射。有透镜系统。利用透镜系统的想法最早是伽利略用来观测星星的。

There are two main flavors of telescope: refractors, which use a lens, and reflectors, which use a mirror.

使用透镜的折射镜和使用单面镜的反射镜。

Since the focal length is the same on both sides, we draw a second ray from the top of the candle, through the F prime focal point, which then refracts through the lens and travels parallel to the axis.

由于焦相同， 我从蜡烛顶部画出第二条光线， 穿过F'焦点，然后通过透镜折射， 并沿轴平行传播。

In 1704, Newton, having written in Latin until that time, chose to write his " Opticks" in English, introducing in the process such words as lens, refraction, etc.

1704年，一直用拉丁文写作的牛顿选择用英文写的《光学》，在这个过程中引入了透镜、折射等词。