[Peter Ward]

Originally Posted by Steffen

For the ignorant among us (i.e. me), could you explain the use of a CaK filter? Is this another type of etalon used instead of the H-alpha one on a solar scope, or is it used in conjunction with a white-light full-aperture filter (such as Baader film), like a solar continuum filter?

EDIT I was assuming the former but the "cheap as chips" made me suspect the latter.

Cheers
Steffen.

Lunt make a module you use rather like a star diagonal.
You can read about them here
http://www.luntsolarsystems.com/cata...-Diagonal.html

Originally Posted by Quark

What a striking image Peter,

There have been some stunning images posted but for me, this is really a standout.

Regards
Trevor

Glad you liked it trevor.