Quote:
Originally Posted by Inmykombie
If I may show my ignorance here,
What is a 4 inch diagonal mirror.
Is it for an extra large aperture scope ?
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Diagonal mirrors are mirrors used as "secondary" mirrors at the top end of the tube of Newtonian reflectors. They are elliptical in shape and come in standard sizes of 1.3 inch (for 6 and 8 inch reflectors), 2.6 inch (for 10 inch reflectors), 3.1 inch (for 12 inch reflectors), and larger for larger telescopes. They are "mass" produced fairly cheaply by opticians with most of the work done by machine to achieve an optically flat surface.
The 4 inch was part of the Meade 16 inch mirror sets sold some years ago. I designed my 16 inch (since sold) to have a fully illuminated view of about 20 mm with a diagonal of 3.1 inch rather than use the 4 inch.
