Jump to content


Photo

Double Star EP Recommendations

  • Please log in to reply
4 replies to this topic

#1 CelestronDaddy

CelestronDaddy

    Viking 1

  • *****
  • Posts: 889
  • Joined: 21 Aug 2009
  • Loc: Central Texas

Posted 26 January 2013 - 12:03 PM

I enjoy double stars and I would like recommendations on EP's to use with my 6SE. Any information would be appreciated... Thanks, Tony

#2 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 22543
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 26 January 2013 - 08:17 PM

Pretty much all eyepieces will be sharp on axis, or close to on axis.
Ergo, the eyepiece you are looking for is an eyepiece that will:
--give you enough power to split the doubles you're examining.
--have a sharp enough image.

Since doubles vary a lot in separation, double stars may be viewed at low, medium, and high powers.
In your scope, with a focal length of 1524mm,
you could use eyepieces of 30mm, 15mm, and 10mm and a good 2X Barlow for the nights when seeing is superb.
As for type, it will depend on your pocketbook, as good eyepieces can be as little as $30 each or as much as $1000 each.
50 degree apparent fields will generally cost you the least. Good 65-70 degree eyepieces will cost more. Some 82 degree eyepieces can be had for the same prices and upwards to $700 or so.
And 100 degree eyepieces can be had for mega$.

There is no such thing as a specific "double star eyepiece", so you'll want to have your eyepieces be good for deep sky, planets, moon, and double stars.
The good news is that, at f/10, just about all eyepieces will do you well, whether TeleVue, Baader, Explore Scientific, Astrotech, pentax, or...........

#3 CelestronDaddy

CelestronDaddy

    Viking 1

  • *****
  • Posts: 889
  • Joined: 21 Aug 2009
  • Loc: Central Texas

Posted 26 January 2013 - 08:33 PM

Don,
Thanks for the reply and information... Tony

#4 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 43392
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 27 January 2013 - 04:18 AM

Don,
Thanks for the reply and information... Tony


Just to add my two cents: Don't be afraid to crank up the magnification to split close double stars. The 50X/in limit is based on the matching of the size of the Airy disk to the resolution of the retina, there is no hard and fast theoretical limit, let your eye tell you what is the best magnification.

For a 6 inch scope, on a night when the seeing is excellent and the scope thermal stable, you might want to use as much as 450x-500x on a Dawes limit, equal magnitude double.

Jon

#5 CelestronDaddy

CelestronDaddy

    Viking 1

  • *****
  • Posts: 889
  • Joined: 21 Aug 2009
  • Loc: Central Texas

Posted 27 January 2013 - 09:45 AM

Don,
Thanks for the reply and information... Tony


Just to add my two cents: Don't be afraid to crank up the magnification to split close double stars. The 50X/in limit is based on the matching of the size of the Airy disk to the resolution of the retina, there is no hard and fast theoretical limit, let your eye tell you what is the best magnification.

For a 6 inch scope, on a night when the seeing is excellent and the scope thermal stable, you might want to use as much as 450x-500x on a Dawes limit, equal magnitude double.

Jon


Jon - Good information and thanks for taking time to reply... Tony






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics