Orion Optics Ultra Grade mirror

Mirror specs: 1/10 wave, 1/66th wave RMS, Strehl 0.99 and 97% reflective protected coating.

Zygo report here: http://www.pbase.com/strongmanmike2002/image/132733331/original

NB: The thin black encircling ring over the very edge of the mirror is to cover the beveled edge
of the glass to avoid any diffraction being set up by the fine ground bevel on the mirror.
Occasionally this can disrupt slightly the images of bright stars. The figure of the optical edge
is fine, its just the last half mm or so where the ground edge can produce a very slight irregular
edge, invisible to your eye but a long exposure can pick it up. The ring can be removed if desired.

The focal length of the mirror is 1181mm and the corrector has a net reducing power of 0.95X
so the final telescope configuration is a 290mm F3.8 with the ring in place, or 297mm F3.78 without.

Email me at: m.sidonio@bigpond.com