View Single Post
  #2  
Old October 18th 04, 09:57 AM
Roger Hamlett
external usenet poster
 
Posts: n/a
Default


"Robert Baker" wrote in message
...
Has anyone used a Denkmeier binoviewer with a Coronado PST?

Two seperate 'issues'. Backfocus, and vignetting. You should be able to
reduce these, by using the Denkmeier 'Barlow' accessory. I have tried
another binocular viewer on a Coronado filter setup (as opposed to the
PST), and without a Barlow, you run into the problem, that the focus
point, is several inches past the blocking filter in the diagonal, leading
to massive vignetting from this. This scope had enough backfocus (I doubt
if this is true of the PST). With a Barlow, it worked quite well, and does
give a suprisingly '3D' feel to some of the forms on the Sun, and the
backfocus requirement fell to the point where I'd have hoped the PST would
be able to handle it. Obviously, with the Barlow accessory, you will only
see a smaller part of the Sun's surface.

Best Wishes