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Star Sweeper Question With WO Accessories

Started by jkurtz555, 12/25/2003 06:11PM
Posted 12/25/2003 06:11PM Opening Post
Has anyone used the Denkmeier Star Sweeper on a C9.25 (newer gray tube) with a William Optic Crayford Focuser and WO 2inch diagonal....I've asked a similar question recently BUT not this specific one....there seems to be some disagreement whether there is enough back focus for this to work on this particular SCT with these accessories. Thanks in advance!
Posted 01/04/2004 05:15PM #1

Since no one else has answered, I'll say this; on my N8 with stock focuser and 2" WO diagonal, there was not enough back focus for the standard f/5 starsweeper. Russ at Denkmeier seemed to think this was the first time this had happened on an 8" SCT. Apparently it has happened on some C9.25s; I infer from the Denkmeier website that some C9.25s come to focus and some do not. If yours doesn't come to focus, Denkmeier has an f/7 starsweeper that requires less backfocus, which they swap for the f/5, (plus $30 in my case, since the f/7 is 2", not 1.25").

Russ was very helpful with my little focus problem, FWIW.

Posted 01/04/2004 07:36PM #2

I was hoping more folks would have jumped in on this one. Have you tried the Cloudy Nights forum? The issue is the combo of the C9.25, crayford focuser and digaonal. Folks have reported not getting a .5 reducer to work with just a diagonal, let alone with a crayford focuser in there. They used a .7 reducer and it worked, but not with a crayford focuser. That might prevent it from working. Also, you have the TV binovue which adds about 3/8" to the path length over the Denks.

I'll bet if you call Russ, he'll send you one to try out. That'll answer the question straight away. Can you lay that OTA on someone's back to see if it focuses?

Clear skies,