Re: [ATM] Secondary Offset

["Mitchell R" <funnybone101@embarqmail.com>]

     Thank you for the website link/explanation/picture. It is much clearer
now.

Another question,

	If I needed a 2.5" secondary minimum, and my offset is .1", and I
get a stock secondary size of 2.6", does that take care of the same problem
offsetting does? Even though the secondary has not moved, the diagonal is
now slightly larger, encompassing the same area as if you had offset it,
albeit not closer to the primary mirror.

	 As Vladimir's excellent diagram shows, offsetting lets you use less
of the lower part of the secondary, and make sure you miss none of the light
cone. A slightly oversized diagonal would encompass any light escaping by a
smaller secondary.

	While technically there maybe more obstruction than if you just
offset .1" isn't much, and it's a standard diagonal size, either way up or
down a size isn't even close.

	Even if the above is incorrect I think for visual use, not
offsetting the secondary wont matter much?

Mitchell 

_______________________________________________
ATM mailing list http://www.atmlist.net/