This meant that the telescope had to be relatively small, with a 45cm primary mirror, and a total weight of 312kg.

In the 1933 the primary mirror was re-figured and a new mount built.

It had the largest monolithic primary mirror in the world from its commission until 2005.

Its largest instrument is a telescope with a primary mirror of 1.6 m which was constructed in the 1960s.

The primary mirror itself is 126" in diameter, but only the center 118" is used.

Note that in these equations D is not the diameter of the primary mirror.

The primary mirror on Webb will be made of beryllium.

The short wavelength end is set by the gold coating on the primary mirror.

As a result, its 94.5-inch primary mirror is almost free of contamination.

The program makes it possible to shift the primary mirror.