GSO ELLIPTICAL SECONDARY MIRROR 70mm

The GSO 70mm elliptical secondary mirror is ideal for amateur telescope makers and is perfectly suited to the Geoptik Nadirus 12" Dobsonian. 

GSO secondary mirrors are offered in sizes from 62.5 - 88mm to suit a variety of primary mirrors. Well known for their excellent quality, GSO mirrors are some of the best available in their price range. The secondary mirror does not come with a holder, but can be glued in place.

The mirrors are made from BK-7 glass with highly reflective aluminium coating (typically 93%) and a protective coating of silicon oxide. GSO guarantees diffraction limited performance with a typical surface quality of 1/12 wave or better.

Each mirror is tested by GSO at the factory with a laser interferometer to ensure it meets their high standards.