Sorry yes, a concave ellipsoid. My memory does not serve me well.
Quote:
Originally Posted by ngcles
Hi David & All,
It needs a concave ellipsoidal secondary. To retain the integrity of the instrument, it should be made of speculum metal like the primary (not glass).
Not impossible by any means but certainly not something you'd buy off the rack ...
Satchmo might be able to comment on the ease or difficulty in obtaining the materials and/or fabrication? Maybe this mob will make you one ?
http://www.interspectrum.ee/off-axis.html
However, you wouldn't restore this telescope to look through (except perhaps for occasional "wind-in-the-hair motoring". The view would be pretty average compared to virtually all the gear people here own. After some TLC, it really belongs in a glass cabinet.
Best,
Les D |