Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Focuser systems...

This topic has been archived. This means that you cannot reply to this topic.
3 replies to this topic

#1 Ken....

Ken....

    Apollo

  • *****
  • topic starter
  • Posts: 1379
  • Joined: 22 Jan 2004

Posted 17 June 2004 - 07:28 PM

I'm in the market for a Maksutov-Cassegrain, and am wondering what the disadvantages/advantages are to the primary mirror focusing system vs fixed primary mirror/external focuser.

Thanks.

Ken....

#2 Suk Lee

Suk Lee

    Aurora

  • *****
  • Posts: 4566
  • Joined: 07 Oct 2003

Posted 17 June 2004 - 07:34 PM

You get virtually unlimited backfocus meaning you can hang all sorts of visual/photographic accessories off the back of the Mak and not run out of backfocus.

Disadvantage is you get image shift as the mirror rocks as it's moved back and forth.

Suk

#3 Ken....

Ken....

    Apollo

  • *****
  • topic starter
  • Posts: 1379
  • Joined: 22 Jan 2004

Posted 18 June 2004 - 07:16 AM

So if I'm planning of using binoviewers, the primary mirror focuser would be the way to go?

Ken....

#4 Suk Lee

Suk Lee

    Aurora

  • *****
  • Posts: 4566
  • Joined: 07 Oct 2003

Posted 18 June 2004 - 02:18 PM

Well, even if you run out of back focus with a fixed mirror Mak, you can usually use a barlow to push the focal point further back, enabling you to come to focus with a binoviewer. The price to be paid is higher magnification, which may or may not be a good thing depending on what you're looking for.

The moving mirror system is definitely the most flexible...


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics