It used to be called a Fresnel lens.

以前叫菲涅尔透镜。

That, Dr Koechlin reckons, gives Fresnel optics a big advantage over Newtonian ones.

凯什兰博士认为，这将是菲涅尔视觉超越牛顿的设计的一大优点。

But Dr Koechlin does not worry about that, because his Fresnel telescope will be in space.

然而，凯什兰博士并不为此担心，因为他的菲涅尔望远镜将会在太空中。

(a special lens that also uses Fresnel optics, and a camera to record the image) must fly at the focus, the accuracy required is only hundredths of a metre, not billionths.

（也是一种运用菲涅尔视觉的特殊透镜，也是一种记录图像的相机）的卫星在焦点上运行，所需要的精准度也只是百分之一米。

Fresnel telescopes have not been developed in the past because the image formed by one that was large enough to rival a useful-sized reflecting telescope would be several kilometres from the zone plate.

过去，菲涅尔设计的望远镜还制造不出来，因为要想使衍射望远镜的大小和正常使用的反射望远镜大小相同，它所产生的图像就会距离波带片数千米远。

And although a second satellite containing the " eyepiece" (a special lens that also uses Fresnel optics, and a camera to record the image) must fly at the focus, the accuracy required is only hundredths of a metre, not billionths.

并且，尽管还必须有一个含有" 目镜" （也是一种运用菲涅尔视觉的特殊透镜，也是一种记录图像的相机）的卫星在焦点上运行，所需要的精准度也只是百分之一米。