It has an aluminized surface that reflects starlight to form an image at the focal plane.

表面镀铝膜，将星光反射到焦平面上成像。

youdao

The results indicate that with the increase of focal length, the intensity distribution on the focal plane varies from central-dip form to Gaussian distribution.

结果表明：随着聚焦距离的增加，焦面光强分布由中央凹陷状向高斯分布转变。

youdao

The refurbished Matthew Steele Court will also form the focal point of a new social history initiative.

BBC: Falkirk Council finishes work on Bo'ness 'Coffin Blocks'