Jump to content


Best eyepiece for excellent viewing conditions?

  • Please log in to reply
6 replies to this topic

#1 Jonathan Hanson

Jonathan Hanson

    Lift Off

  • -----
  • Posts: 19
  • Joined: 19 Apr 2014

Posted 02 July 2014 - 07:45 PM


I have a Questar 3.5 with the two standard eyepieces. I've been spending some time in the Rockies at 10,000 feet or more, with superb viewing, and I'm thinking I might be able to push the magnification a bit on planets. What are your recommendations?



#2 TerryWood


    Viking 1

  • *****
  • Posts: 691
  • Joined: 15 Mar 2012
  • Loc: Blue Ridge Mountains, USA

Posted 02 July 2014 - 08:16 PM

If seeing is super duper, you could use an 8mm. But it gets pretty dim at those magnifications. My favorite is the 12mm. Then if seeing is really good I flip the Barlow lever and take it up a notch. Brandon eyepieces in those sizes do a nice job. A 10mm or 13mm Ethos also provide outstanding views. You may need the wrap around counterweight on the front of the tube (those eyepieces are heavy). You can probably get by without it, but it is nice to have just in case. Just my opinion. 10,000 feet must be incredible!



#3 John F

John F

    Viking 1

  • *****
  • Posts: 637
  • Joined: 16 Feb 2004
  • Loc: Washington State

Posted 02 July 2014 - 11:25 PM


If you're using the two standard eyepieces with the Q (and I assume its built-in Barlow) then your current highest power (with the 16mm Brandon) should be 128x. The next logical step up from that would be 160x with an 8mm eyepiece and from my experience with that scope and power I would recommend it.

However, on many night of the year I find the seeing condition to be too unsteady to use 160x so I'll use 128x or 107x depending on the conditions) instead. Over the past year or so I've been using 12-10-8mm Radians with the Q to get these powers (and without having to use the Barlow) and I've been quite pleased with them. They're not super large of heavy like the Ethos eyepieces and but they still have a significantly wider field than the Brandon's and much more eye relief.

John Finnan

#4 Jonathan Hanson

Jonathan Hanson

    Lift Off

  • -----
  • Posts: 19
  • Joined: 19 Apr 2014

Posted 05 July 2014 - 03:52 PM

Thank you both! Those are the kinds of suggestions I was hoping for.

#5 Steve's 50th

Steve's 50th

    Explorer 1

  • -----
  • Posts: 72
  • Joined: 30 Jul 2011

Posted 07 July 2014 - 05:45 PM

I agree with Terry, 12mm is about the max you can use consistently. I also have a 8mm but rarely get a chance to use it, and most of the time when I try it I end up going back to the 12mm. If there were a 10mm Brandon I would sure like to try it, since many times I've thought the 12mm didn't max out the seeing conditions and the 8mm was just a little too much.

#6 Jonathan Hanson

Jonathan Hanson

    Lift Off

  • -----
  • Posts: 19
  • Joined: 19 Apr 2014

Posted 09 July 2014 - 10:45 AM

Thanks Steve. I definitely don't want to go too far with magnification and find myself with an eyepiece I rarely use.

#7 Mike Allen

Mike Allen

    Lift Off

  • *****
  • Posts: 24
  • Joined: 05 Jan 2008
  • Loc: Ohio

Posted 20 July 2014 - 10:53 AM

I agree with John F. 16 Brandon is good for general deep sky. 16 with internal barlow gives close to ideal exit pupil for planets. 8 is great for double stars, or maybe planets on a very steady night. I rarely use 8 with barlow except on very tough doubles on an exceptional night.

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.

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics