Results 1 to 9 of 9
  1. #1
    Ed L.'s Avatar
    Ed L. Guest

    Default Experiences with Orion Expanse EP



    A few months ago I bought a pair of Orion Expanses (2nds) and tripled
    the size of my EP collection.

    I started with a TV 32mm Plossl and added the Expanse 20mm and 9mm.

    All my observations are with a C5+ (125mm f/10). I wear glasses, and
    have enough astigmatism to make wearing my glasses observing
    nessesary.

    I like the eye relief of both of my expanses, and found them
    comfortable to use under most conditions, however, the 9mm is shorter
    than the 20mm by a couple of mm easily. Both Expanses are close to
    parafocal.

    My favourite of the two is the 20mm, I find that it gives a lovely
    view of most objects, and offers a nice wide AFOV (66deg) and a the
    same TFOV of my 32mm plossl (approx 1deg). I've not noticed any
    significant distortions around the edge, and I found that objects are
    a bright in it as my plossl.

    I am not so happy with my 9mm. My greatest disappointment with it is
    it's lack of brightness. For example, when looking at the moon (1st
    quarter) with the 20mm I felt that the colour was good, and matched
    what I saw with the naked eye. The 9mm on the other hand
    significantly dimmed the view, and introduced a apparent red colour to
    the surface.

    I further found that I prefered the views that I have with the 20mm in
    a 2x barlow, rather than using my 9mm. I think the images were
    cleaner and simply more enjoyable, inspite of the refocus.

    Perhaps someone might suggest a fix that I might try with the 9mm, but
    I think this EP is destined to collect dust in my case.

    Clear skys,
    Ed L.

  2. #2
    Jon Isaacs's Avatar
    Jon Isaacs Guest

    Default Experiences with Orion Expanse EP

    >Perhaps someone might suggest a fix that I might try with the 9mm, but

    My experience with my 9mm Adorama Ultra Widefield (same as the expanse) is not
    at all like yours. It is a decent eyepiece with good brightness, reasonably
    sharp at the edge. Of course brightness does decrease significantly as the
    magnification increases. The 9 mm should be giving you an exit pupil of 0.9
    mm, not so huge and a magnifaction of about 140X, getting up there for a 5 inch
    SCT, central obstruction and all.

    What does the eyepiece look like when you just look through it at a light?

    Have you unscrewed the barrel, the bottom section (chrome plated section) comes
    off and contains a lens assembly. Might take a look in there as see what you
    see.

    jon

  3. #3
    Shneor Sherman's Avatar
    Shneor Sherman Guest

    Default Experiences with Orion Expanse EP

    eladner@yahoo.com (Ed L.) wrote in message news:<daba33a4.0308050808.1524f928@posting.google. com>...

    My experience with the 9mm Ultrawide (I have a pair) is quite
    different. Ten nights ago, my 9mm Ultrawide beat a 9mm Nagler Type 1
    in two 22" scopes; the owner of the Nag agreed that the Ultrawide gave
    a sharper, brighter image. The only advantage the Nagler had was a
    wider field of view.
    Clear skies,
    Shneor Sherman

  4. #4
    Jon Isaacs's Avatar
    Jon Isaacs Guest

    Default Experiences with Orion Expanse EP

    >My experience with the 9mm Ultrawide (I have a pair) is quite

    My experience is that of the 6, 9 and 15, the 9 is the nicest eyepiece. The
    9mm has the built-in Barlow/Symthe lens which makes the entire field quite
    sharp. Adding a barlow to the 15 improves the edge sharpness but of course
    then it is a 7.5 mm eyepiece...

    Just my experiences

    jon

  5. #5
    Mike Wagenbach's Avatar
    Mike Wagenbach Guest

    Default Experiences with Orion Expanse EP

    jonisaacs@aol.com (Jon Isaacs) wrote in message news:<20030805124108.20076.00000992@mb-m29.aol.com>...
    But none of this should be excessive. In my Orion mak, with similar
    aperature and obstruction, I use a 10 mm Kellner (156x), 9 mm Nagler
    (171x) and occaisionally 7 mm ortho (223x) and while the later is
    clearly pushing things, it's not a real problem. On the moon, all the
    images are plenty bright, color-free and reasonably sharp. My 12.5 mm
    ortho often gives an easier image, but that's a combination of less
    critical focusing and lousy seeing.

    There must be some other problem here. I don't have the 9 mm Expanse,
    so it could be specific to that EP. I have no problem with the 6 mm
    Expanse, though it's excessive in the mak.

  6. #6
    Shneor Sherman's Avatar
    Shneor Sherman Guest

    Default Experiences with Orion Expanse EP

    jonisaacs@aol.com (Jon Isaacs) wrote in message news:<20030806130912.02307.00001069@mb-m21.aol.com>...

    Interesting. Pete Rasmussen recently wrote that he thought the 15mm
    was the best of the set. I wonder if there's adequate QC on these.
    Clear skies,
    Shneor Sherman

  7. #7
    Rod Mollise's Avatar
    Rod Mollise Guest

    Default Experiences with Orion Expanse EP

    >Interesting. Pete Rasmussen recently wrote that he thought the 15mm

    Hi:

    Maybe. Maybe not. The thing is, the more I hear folks opinions on eyepieces,
    the more I think opinions on them are an intensely personal thing. One man's
    treasure...


    Peace,
    Rod Mollise
    Author of _Choosing and Using a Schmidt Cassegrain Telescope_
    Like SCTs and MCTs?
    Check-out sct-user, the mailing list for CAT fanciers!
    Goto <http://members.aol.com/RMOLLISE/index.html>

  8. #8
    Jon Isaacs's Avatar
    Jon Isaacs Guest

    Default Experiences with Orion Expanse EP

    >Maybe. Maybe not. The thing is, the more I hear folks opinions on eyepieces,

    As usual, the voice of wisdom from Uncle Rod... Now if we could just wean him
    off those damn SCT's.... :-)

    There are so many variables that must be included in eyepiece preference that
    it must be just a personal choice.

    The 15mm is a nice eyepiece, I just like the 9 mm better..

    jon

  9. #9
    Ed L.'s Avatar
    Ed L. Guest

    Default Experiences with Orion Expanse EP

    Jon,

    When I get home, I'll give the 9mm EP a close look. I've called Orion
    and Marhsal there tells me that I shouldn't be getting the red
    colouring that I've described, but that with the higher power, I will
    be getting a slightly dimmer view.
    I still think that there is something wrong with it as the 20mm with
    barlow is so much brighter than the 9mm.
    Baring something obvious, I'll be sending the 9mm back for a
    replacement, and hopfully I'll get a 9mm that I will enjoy.
    I will try looking though it at a light, like you suggested, and
    report back.

    Ed L.

    jonisaacs@aol.com (Jon Isaacs) wrote in message news:<20030805124108.20076.00000992@mb-m29.aol.com>...

 

 

Similar Threads

  1. Orion Expanse Eyepiece
    By powerwindows1985 in forum Telescope Eyepieces Forum
    Replies: 4
    Last Post: 09-10-2008, 09:26 PM
  2. The 98 degree 7x32 Orion Expanse binos
    By Doug Peterson in forum Amateur Astronomy Forum
    Replies: 3
    Last Post: 10-22-2003, 01:46 PM
  3. Orion Expanse Wide-Field eyepieces
    By ds in forum Amateur Astronomy Forum
    Replies: 6
    Last Post: 08-26-2003, 04:20 PM
  4. Orion Expanse E.P. Review
    By Bill Greer in forum Amateur Astronomy Forum
    Replies: 13
    Last Post: 07-27-2003, 11:26 PM
  5. Orion Expanse E.P. Review
    By Rod Mollise in forum Amateur Astronomy Forum
    Replies: 0
    Last Post: 07-25-2003, 10:46 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 07:01 AM.