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Old 06-11-2017, 02:31 PM
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Allan_L (Allan)
Member > 10year club

Allan_L is offline
 
Join Date: Mar 2008
Location: Central Coast NSW
Posts: 3,336
Quote:
Originally Posted by drrockso View Post
Hey Folk!
Thanks for building up such an informative community. It has been very helpful so far.
I recently bought a used 150EQ. It was nice and cheap and meant that if we (the family) lost interest, our buy in was low. The mount is a bit wobbly (even wind) and the finder scope is utter rubbish(plastic with so much play that adjusting it using the knobs moves the FS in its mount completely moving alignment). But the scope works :-)
But as it seems, I need more. Last night we managed to see Saturn through the 10mm EP and that was great but man it was small. So i'm looking to buy new Barlow I think, to double or triple the existing 10&20mm EPs we have.
Now I dont particularly want to buy more cheap ... stuff so what would be recommended and while i'm asking questions. Does the Barlow affect the FoV at all?
I understand I will be spending more then I did on the scope on any EPs and Barlow's and I guess that's ok.
Cheers all
John
Hi john,
Welcome to IceInSpace
(from a fellow bean-counter).

Your current scope 150mm aperture 750mm focal length 10mm eyepiece will be giving you approximately 75 times magnification with a true field of view of about .67 of a degree ( or 40 arc minutes). [assuming a plossl with 50 degree apparent field of view].

With that setup, you could add a 2 times barlow and get a satisfying 150 magnification, and your field of view is halved to about .33 of degree.
Any further magnification may not be so satisfying.
Problem is, with a shaky mount the wobbles will be amplified and the target will pass through the field of view pretty quickly.
Not to mention atmosphere instability probably means you get a larger image but not clearly defined.

I mainly use Televue eyepieces (circa $450 and up), but there are a lot of people here who use more economical brands and claim as good results.
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