Dismiss Notice
New Cookie Policy
On May 24, 2018, we published revised versions of our Terms and Rules and Cookie Policy. Your use of AstronomyConnect.com’s services is subject to these revised terms.

More Views

GSO 1.25" SuperView Eyepiece - 20mm

4.4 (18 Reviews) Read Reviews Write Review
Brand GSO
Part Number SV20
Availability available

Product Info

Manufacturer Description

Since their introduction in the US market a few years ago, the GSO SuperView series of wide-field eyepieces have taken the amateur astronomy community by storm. These are, by far, the best-selling GSO eyepieces. With an expansive apparent field of view (AFOV) ranging from 60 - 68 degrees, users will experience incredible views without breaking the bank or impinging on your scope's balance.  SuperView eyepieces are available in 2 barrel sizes (1.25" or 2') and 5 focal lengths (ranging from 15mm to 50mm).

Images are virtually free of chromatic aberration or pincushion distortion with excellent flatness of field and eye relief. These eyepieces feature rubber grips on the housing and foldable rubber eyeguards. All eyepieces are fully multicoated, have blackened lens edges for improved contrast, and come with two end caps.

Guan Sheng is a leader in optical telescopes and accessories and their products have been sold for years by the "Big Three" (Meade, Celestron and Orion) under their own brand names. Give these a try - you will not be disappointed!

Reviews

4.4 (Based on 18 Reviews) 94% of reviewers recommended this product.
Rating Distribution
Sort by
  • Date
  • Rating
  • Useful
    1. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by James K.
      1521517174
      Mar 19, 2018

      4.0 Very nice eyepiece for the money.

      Pros:

      Cons:

      Comments:

      A good value.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    2. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Brent S.
      1483467326
      Jan 3, 2017

      5.0 GSO 1.25" Superview Eyepiece 20 mm

      Pros:

      Cons:

      Comments:

      I love this eyepiece!!!! It provides superb views in all my telescopes, (24" on down) and doesn't adversely affect the balance in any of them, even my smallest reflectors (3") and refractors (2.4") telescopes.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    3. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by AstroPengi of Sparks NV.
      1437955200
      Jul 26, 2015

      5.0 Love 'n This 20mm Gem

      Pros:

      Strong Construction,Quality Lenses,Lightweight

      Cons:

      Comments:

      Using this 20mm in my 127mm F/12 Mak. Super eye relief, and wonderful sharp images! Thanks Agena for the quick shipping and quality product!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    4. William Bryce

      William Bryce New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by tell08 of Toronto, Canada.
      1413763200
      Oct 19, 2014

      4.0 Great wide view for the price

      Pros:

      Easy to Use,Strong Construction,Wide-field,Price

      Cons:

      Tricky Eye Relief

      Comments:

      Very useful eyepiece that works great in my 8inch Dob and also works well in my small Meade ETX 90. Great focus in the center of the eyepiece but a little soft on the edges - but really for the price it is a great find.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    5. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by RonVen of New York.
      1386374400
      Dec 6, 2013

      5.0 Great eyepiece

      Pros:

      Quality Lenses

      Cons:

      Comments:

      GSO makes quality eyepieces and this 20mm does not disappoint. I look forward to many years of use.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    6. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by GraemerD of Gloucester, UK.
      1325548800
      Jan 2, 2012

      5.0 Great Lens & Great Delivery Overseas

      Pros:

      Accurate,Quality Lenses,Strong Construction

      Cons:

      Comments:

      My second purchase from Agena - I'm in the UK and delivery was less than a week which is great. Second, the GSO lens I bought is really good - sharp optics and a real quality feel to the construction. It's a wide angle lens I bought for galaxy viewing and it's perfect for that and as low mag finder eyepiece for when your looking for something smaller.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    7. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by killerkrom of Abbotsford, BC.
      1303344000
      Apr 20, 2011

      4.0 Excellent quality eyepiece

      Pros:

      Accurate,Quality Lenses,Strong Construction

      Cons:

      Comments:

      This is an excellent quality eyepiece. It yields very sharp views to almost the outer edge. The eyepiece had great contrast and great color. I am very impressed with this eyepiece, and the low price is just gravy :)

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    8. Nubcaek

      Nubcaek New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Herp Mc Derp of Bellflower, CA.
      1274227200
      May 18, 2010

      4.0 Good wide view entry eyepiece

      Pros:

      Strong Construction,Quality Lenses,Accurate

      Cons:

      Best on slow focus scopes

      Comments:

      This eyepiece looks good to me and feels quality. I like using it for everything but you need a right side up prism for terrestrial use on a refractor. These more budget wide field eyepieces are best on slow focus telescopes f/8 or greater, I used a small f/10 and it looks great to me.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    9. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Ray of Columbus, GA.
      1272672000
      Apr 30, 2010

      5.0 Nice ep

      Pros:

      Accurate,Quality Lenses,Strong Construction,Compact

      Cons:

      Comments:

      Bought to replace one that I gave to a newcomer that purchased a scope from me. Decent images at a great price.

      Bottom Line: Would you recommend this item? No
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    10. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by dwmedic of Kansas.
      1249603200
      Aug 6, 2009

      4.0 Really nice eyepiece

      Pros:

      Quality Lenses,Strong Construction

      Cons:

      Comments:

      This was my first GSO eyepiece and is still the eyepiece I use the most. Great FOV and eye relief. Another must have.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    11. rustydog50

      rustydog50 New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      1243755960
      May 31, 2009

      4.0 Good in F/10 or longer focal length scopes

      Pros:

      Price, Good in longer f/l scopes, Wide FOV

      Cons:

      Disappointing in fast scopes

      Comments:

      I inherited this eyepiece when I bought a used 10 f/5 dob (Hardin aka GSO). I was very disappointed with its performance, especially since the 30mm GSO superview gives super, sharp views in that scope. This eyepiece has a hard time even bringing stars to pinpoints in the middle of the FOV and in the outer 50% forget it. So, I would definitely not recommend this in fast scopes. That said, the views in my ETX-125 (f/15) with this eyepiece are stunning. Field is sharp with pinpoint stars through almost all the field. This is my primary eyepiece for that scope (and I have Naglers). Without a doubt, this is the eyepiece to get for a long focal length scope like that. How can you go wrong with the price and wide FOV? Cool green coatings are nice to look at, too.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No
    12. jcrstarguy

      jcrstarguy New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by John R. with Black River of North Ridgeville, Ohio.
      1243468800
      May 27, 2009

      4.0 An Excellent Eyepiece For The Price

      Pros:

      Quality Lenses,Compact,Strong Construction

      Cons:

      Comments:

      The GSO 20mm Superview provides superior performance compared to standard plossl eyepieces; wider field of view with better eye relief and a much larger exit pupil with comparable corrections to most plossls on the market.
      An excellent choice for general viewing at a great price.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    13. AstroGuy1

      AstroGuy1 New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Bassab of Idaho.
      1237852800
      Mar 23, 2009

      4.0 1.25" GSO 20mm Superview from Agena

      Pros:

      Sharpness of image,Eye relief,Wide FOV

      Cons:

      Tinge of false-color

      Comments:

      This was my first purchase from Agena Astroproducts. The eyepiece's visual appearance and quality is very good. All elements appear to be edge coated and highly polished. The wide field is a welcome increase from Plossls and image sharpness is quite good even out to near the edges. Eye-relief is just right. I am not an expert observer, but would rate this eyepiece quite high especially considering the cost.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    14. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by mhuston6 of Florida.
      1227830400
      Nov 27, 2008

      4.0 GSO SuperView 20mm

      Pros:

      Nice FOV,Nice EP for the price

      Cons:

      Some false color

      Comments:

      I like this 20mm SuperView but it shows a little more false color than the regular 1.25" GSO EP! Nice eyepiece for the price.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    15. AstroGuy1

      AstroGuy1 New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by hansolo of Pennsylvania.
      1226966400
      Nov 17, 2008

      5.0 One of the best buys in an eyepiece

      Pros:

      Great all around EP,Very crisp clean views

      Cons:

      None

      Comments:

      This was the first EP that I bought to add to the two eyepieces that came with my scope. I have to say I absolutely love this eyepiece. I have had it for over two years and it is, by far, my most used eyepiece.

      I have used this many times in my Orion Shorty barlow and these two work very well paired together with no coma or problems to report. If I could ever afford Televue eyepieces, this is one eyepiece that I still would not give up. This EP gives great views of Saturn.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    16. hansolo

      hansolo New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      1204191960
      Feb 28, 2008

      5.0 This is one of the best buys in an eyepiece that I have found

      Pros:

      Great all around EP, very crisp clean views

      Cons:

      None

      Comments:

      This was the first EP that I bought to add to the two eyepieces that came with my scope. I have to say I absolutely love this eyepiece. I have had it for over two years and it is, by far, my most used eyepiece.

      I have used this many times in my Orion Shorty barlow and these two work very well paired together with no coma or problems to report. If I could ever afford Televue eyepieces, this is one eyepiece that I still would not give up. This EP gives great views of Saturn.

      I bought this eye piece from Owl Astronomy but they no longer are a dealer of Superviews so I purchased my 15mm Superview from Agena AstroProducts.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No
    17. bassab

      bassab New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      1184590440
      Jul 16, 2007

      4.0 1.25" GSO 20mm Superview from Agena Astro

      Pros:

      67 degree field, sharpness of image, and eye-relief

      Cons:

      Tinge of false-color?

      Comments:

      This was my first purchase from Agena Astroproducts. The transaction was very smooth, shipping was free, and I received my eyepiece in 3 days. The eyepiece's visual appearance and quality is very good. All elements appear to be edge coated and highly polished. The 67 degree field is a welcome increase from Plossls and image sharpness is quite good even out to near the edges. Eye-relief is just right. I am not an expert observer, but would rate this eyepiece quite high especially considering the cost.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No
    18. mhuston6

      mhuston6 New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      1178713440
      May 9, 2007

      4.0 GSO SuperView 20mm

      Pros:

      Nice EP for the $$ and has a nice FOV

      Cons:

      False color

      Comments:

      I like this 20mm SuperView but it shows a little more false color than the regular 1.25" GSO EP! Nice eyepiece for under $35.00

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No
    Sort by
    • Date
    • Rating
    • Useful

      Specifications

      Apparent Field of View 68°
      Barrel Size 1.25" (31.7mm)
      Bolt Case Included Yes - Free Agena Eyepiece Container
      Bolt Case Size Agena 42x80mm
      Coatings Fully Multi-Coated
      Height (with Eye Guard) 78mm
      End Caps 2
      Eye Relief by Design 18mm
      Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6)
      Focal Length 20mm
      Lens Elements 5
      Lens Groups 3
      Rubber Eye Guard Yes
      Blackened Lens Edges Yes
      Manufacturer GSO
      Eyepiece Focal Length 15.1mm - 20mm
      Eyepiece Field of View 61 - 70 degrees
      Eyepiece Series GSO SuperView
      Barrel Type Smooth sided
      Eyepiece Weight 5.70oz (161.59g)