[APML]: Coma correctors

[sdilling@ford.com (Stephen Dillinger)]

I've got a question about coma correctors for the collected wisdom of the
astrophoto list.  There are at least 3 different commercial solutions to this,
the first is the Televue Paracorr for US$240 or so, the next is Lumicon's
answer for US$285, the last one I know of is the Celestron unit which is
discounted for US$99.

Obviously, the question is do you get what you pay for?  The Celestron unit is
only ~40% of the cost of the others, but is it adequate for photography?

The second question relates to the difference between the Televue and Lumicon
versions.  With an f/4 primary, which will perform better?  Or will both
perform well?

I'm assuming that there's no "right" answer here, I'm just fishing for the
relative strengths and weaknesses of each unit.

Thanks,

Steve