佳能的这款单反相机专用折反镜头采用了一组折反镜片，以及一个跟棺材差不多大的镜身，其焦距被拓展到5150mm。

Using a group of mirrors and a housing that's almost big enough to use as a coffin, Canon was able to stretch the focal-length on this SLR-specific lens to 5,150mm.

youdao

佳能的这款单反相机专用折反镜头采用了一组折反镜片，以及一个跟棺材差不多大的镜身，其焦距被拓展到5150mm。

Using a group of mirrors and a housing that's almost big enough to use as a coffin, Canon was able to stretch the focal-length on this SLR-specific lens to 5,150mm.

youdao