Quote:
Originally Posted by Indio
While I dont know for sure I think my focuser will only take 1.25 eyepieces. I unscrewed the eyepiece holder and the barrel only measures 42mm inside dia.
Looking at the other 150mm in the same brand (Skywatcher) the 750mm version looks to have a different focuser and its listed on the web site as taking 2" or 1.25. Is upgrading my focuser to a 2" even worth considering?
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Hi,
I guess this must be the telescope you bought then:-
http://www.ozscopes.com.au/skywatche...telescope.html
And it does only come with a 1.25" focuser (sorry wavy) . Most of the 1/2 decent 6" scopes these days all have a 2" focusers
http://www.skywatcheraustralia.com.a...53mm-f-1200mm/
http://www.skywatcheraustralia.com.a...150mm-f-750mm/
I wouldn't worry about upgrading the focuser at the moment. I think that would be burning money on a scope you will probably want to upgrade in the next 12 to 18 months if you stay with the hobby. There are a few reasons for this which will become apparent to you as you learn more about the hobby over the coming months.
This means you need to stick with 1.25" eyepieces. This is a bit limiting by todays standards but not the end of the world. 25 years ago 1.25" focusers were standard fare on both large and small scopes, but not today. It's a bit like saying an EH Holden (1964) was a great car. Well in 1964 it was, by todays standards and compared to modern cars its not something I would get around in. Alex has already given you sound advice regarding the AFOV. With a 1.25" focuser you are limited to an eyepiece having a product of its focal length and AFOV limited to about 1650. What I mean by this is you multiply the eyepiece focal length in mm by its AFOV in degrees and the product needs to be under 1650, otherwise you do not gain any True Field of View. For instance with a 24mm Televue Panoptic having an AFOV of 68 degrees and a focal length of 24mm its product is 1632, which as Alex correctly pointed out, is about maximum for a 1.25" eyepiece. If you went with a Plossl type eyepiece having a 52 deg AFOV you can go to a maximum focal length of about 32mm. On that basis I would be looking at some second hand eyepieces like the Vixen 22mm LVW, Televue 24mm Panoptic or a 30mm plossl type like the Orion Ultrascopic or Celestron Ultima.
Cheers,
John B