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Agena 1.25" Super Wide Angle (SWA) Eyepiece - 20mm

4.6 (22 Reviews) Read Reviews Write Review
Brand Agena AstroProducts
Part Number E-AG-SWA20
Availability available

Product Info

Manufacturer Description

Looking for $400 performance in an under-$100 eyepiece? Then you can look no further.

With features like a wide 70 degree apparent FOV, five elements of fully multi-coated high-index glass, beautiful black anodized body and barrel, the Agena Super Wide Angle (SWA) eyepieces are as close as you can get. These eyepieces will give you crisp and wide views of the Moon, planets, galaxies, nebulae, and star clusters, rivaling the performance of much higher priced eyepieces.

Features:

  • 70 degree apparent field of view, for that immersed in space feeling
  • Available in 1.25" (10, 15 and 20mm focal lengths) and 2" (26, 32 and 38mm) formats to cover a wide range of magnifications and true fields of view
  • Super sharp, with excellent aberration correction and extremely high resolution rivaling higher-priced eyepieces
  • Blackened lens edges, anti-reflection threads for maximum image contrast
  • Fold-down rubber eyecups, rubber grip rings for comfort and safety
  • Sleek black barrel with safety undercut to reduce the possibility of the eyepiece slipping out of the focuser or diagonal
  • Light in weight for their size, thus minimizing or eliminating the need to rebalance your telescope

See why Erik Wilcox, reviewing the Agena SWA 2-inch eyepieces for Astronomy Technology Today magazine [Oct. 2007, pp. 36-38], said:
All these three eyepieces offer a great value, with a lot of "bang for the buck." Agena AstroProducts has really raised the bar with this line, and in the under $100 category, I feel that it would be difficult to find another line of 2-inch eyepieces that offer better performance for the price.

Reviewing our 20mm 1.25-inch SWA eyepiece on Cloudy Nights [Jun. 2007], Nathan Melendez concluded:
"Excellent performance in an inexpensive package. Highly recommended whether you wear glasses or not. These are great all purpose eyepieces...an incredible buy!!"

Reviews

4.6 (Based on 22 Reviews) 86% of reviewers recommended this product.
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    1. Guest

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      Review by William S.
      1522077637
      Mar 26, 2018

      5.0 A great wide field eyepiece for my long refractors.

      Pros:

      Cons:

      Comments:

      I have found this eyepiece to work very well in my long refractors. The image is good all the way to the very edge.

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

      This review was provided courtesy of AgenaAstro.com

    2. Guest

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      Review by Dean G.
      1516067473
      Jan 15, 2018

      5.0 Great eyepiece

      Pros:

      Cons:

      Comments:

      Sharp in the center less so on the edge. Works well with F7.5 and F10 scopes.

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

      This review was provided courtesy of AgenaAstro.com

    3. Guest

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      Review by miracle man of Spokane, WA.
      1435363200
      Jun 26, 2015

      4.0 A bargain

      Pros:

      Accurate,Quality Lenses,Lightweight,Strong Construction,Easy to Use

      Cons:

      Comments:

      70 degrees is nice. Any more field and you would have to press your eye against the eyecup. The extra field makes it much easier to find objects and keep them centered. This one is sharp out to the edge.

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

      This review was provided courtesy of AgenaAstro.com

    4. Guest

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      Review by John of Tucson, AZ.
      1414454400
      Oct 27, 2014

      5.0 Great eyepiece

      Pros:

      Accurate,Easy to Use,Strong Construction,Quality Lenses

      Cons:

      Comments:

      Well made eyepiece with excellent coatings. Sharp to the edge in f/8 & f/7 refractors.

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

      This review was provided courtesy of AgenaAstro.com

    5. Guest

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      Review by Chuck of Brook Park, Ohio.
      1413590400
      Oct 17, 2014

      5.0 Agena 20mm SWA Eyepiece

      Pros:

      Lightweight,Quality Lenses,Strong Construction,Easy to Use

      Cons:

      None

      Comments:

      Got this so I could do eyepiece projection prominence photography with my Ha solar telescope. I also have the SWA 15mm but wanted the wider field of view this 20mm eyepiece provides.

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

      This review was provided courtesy of AgenaAstro.com

    6. Guest

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      Review by ABHAT of Middletown MD.
      1408147200
      Aug 15, 2014

      3.0 Not as good as other agena wide angles.

      Pros:

      Easy to Use,Strong Construction,Lightweight,Compact

      Cons:

      Difficult To Focus,Difficult to Use

      Comments:

      Lot of coma at the edges. Very small portion in the middle is good. Works well with slow scopes f/8 or higher. I would not use this EP for f/6 or f/5s.

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

      This review was provided courtesy of AgenaAstro.com

    7. Guest

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      Review by Aaron the stargazer of Twin Falls, ID.
      1405209600
      Jul 12, 2014

      4.0 Test run in f/5 scope, and compared to ot

      Pros:

      Lightweight,Quality Lenses,Strong Construction,Compact

      Cons:

      Difficult to Use

      Comments:

      I bought this recently from AgenaAstro. It arrived a few days after order. When I first got it, I thought it was hard to see the full field of view. However, after getting my eye placed just right, I now see that it is indeed 70 degrees or clearly larger than my 60 degree binoculars. I can see about 90% of the field of view with my glasses on, which eat up 18mm.

      Seeing the full field of view from different angles is much easier in my Plossl. However, even looking through the SWA with the wrong eye placement and seeing only part of the field of view, it is still much larger than that of the Plossl.

      Eye placement in my 60 degree binoculars is much easier, as is seeing the full field without glasses. My binocular edge can black out a bit when I try to look at it directly, but I don't feel as tempted to look there because I can see it more easily in my peripheral vision being closer to the center. With glasses, I see less than 50% of the field of view in my 60 degree binoculars. It takes some looking back and forth and finding the right eye placement to see that the 70 degree is larger than the 60 degree, but once found, the 70 degree clearly is better.

      I've looked through 82 degree eyepieces before, and felt them getting bigger as I got closer until I was not sure if I should get closer. I've also looked through 100 degree eyepieces. The eye relief on those is too short to see the full field of view. But you can see the edges just fine simply by moving to the side and looking at an angle. I can even do that a bit with the 70 if I get in the right location. I looked through a Panoptic 35mm and found it much more immersive than this 20mm SWA.

      As for sharpness, I have not yet done a star test. I put it in an f/5 refractor on a tripod, 80mm x 400mm, and looked at the moon and Saturn and some tree leaves. The moon looked plenty sharp in the center. When I moved it near the edge, it was much softer, and there was some lateral chromatic aberration. However, these were only noticeable when I looked at it directly. I could not tell with my peripheral vision. The edge sharpness is plenty good enough to find your way around the stars and not be distracted. At 20x, I could not tell that Saturn has rings in the center of the view, though I was not expecting to at 20x. My 25x70 binoculars just barely show ears. With other eyepieces in longer scopes, I've seen Saturn as a tiny ball in a tiny ring at 35x. Finally, the distant tree leaves. The leaves looked very good in the SWA.

      The eyepiece is small and light and sturdy. It looks good quality. I looked inside, and the field stop is as wide as the inside of the barrel. Basically, I see a big lens, not a field stop, same as my 32mm Plossl. The reflection control is excellent. I can see far less of my reflection in this eyepiece than in my coated binocular objectives. The inside is very black. For the price the quality is very good.

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

      This review was provided courtesy of AgenaAstro.com

    8. Paul Schofield

      Paul Schofield New Member

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      Review by Paul of North Carolina.
      1402358400
      Jun 9, 2014

      5.0 Quality at a great price

      Pros:

      Quality Lenses,Easy to Use,Accurate,Strong Construction,Compact,Lightweight

      Cons:

      Comments:

      I am pleased with the quality of construction, coatings, and performance of this eyepiece. It is sharp to the edge in my f/9.3 and f/11.4 refractors. The image is great nearly to the edge in my f/6.6 Newtonian. Lightweight, easy eye placement, and good contrast make this an enjoyable eyepiece to use. With my 3x barlow it also becomes a 6.7mm SWA. Great price and service from Agena. Thanks again.

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

      This review was provided courtesy of AgenaAstro.com

    9. Guest

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      Review by Jaws of Royersford, PA.
      1386460800
      Dec 7, 2013

      5.0 Good eyepiece at a good price!

      Pros:

      Accurate,Strong Construction,Quality Lenses,Compact,Lightweight

      Cons:

      Comments:

      Exactly what I was looking for. A nice quality wide angle eyepiece that is easy to use, inexpensive, and easy to focus.

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

      This review was provided courtesy of AgenaAstro.com

    10. Guest

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      Review by Atom B of Phoenix, AZ.
      1386374400
      Dec 6, 2013

      4.0 Good value for long focus scopes

      Pros:

      Cons:

      Comments:

      Good budget conscious choice for SCTs, Maks and slow refractors. Decent eye relief. Nice coatings. Very lightweight. A lot for little money.

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

      This review was provided courtesy of AgenaAstro.com

    11. Guest

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      Review by phliperfil of Cumberland Ontario Canada.
      1375488000
      Aug 2, 2013

      5.0 Good lens

      Pros:

      Quality Lenses,Accurate

      Cons:

      Comments:

      This lens is better than most expensive lenses out there ... I hate paying for name instead of quality ... for the price this eyepiece is better than most more expensive eyepieces

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

      This review was provided courtesy of AgenaAstro.com

    12. Guest

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      Review by Mauricio MTYMAK of Monterrey, Mexico.
      1336867200
      May 12, 2012

      5.0 MY FAVOURITE EYEPIECE

      Pros:

      Easy to Use,Accurate,Compact,Strong Construction,Quality Lenses,Lightweight

      Cons:

      Comments:

      I Recently bought this Agena SWA 20mm 70

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

      This review was provided courtesy of AgenaAstro.com

    13. georgetatsis

      georgetatsis New Member

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      Review by AstroGeorge of Europe.
      1319846400
      Oct 28, 2011

      5.0 A gem!

      Pros:

      Quality Lenses,Lightweight,Accurate,Strong Construction

      Cons:

      Comments:

      Will never sell it again!

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

      This review was provided courtesy of AgenaAstro.com

    14. Guest

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      Review by Chris M of Los Angeles.
      1307577600
      Jun 8, 2011

      4.0 Great Value

      Pros:

      Strong Construction,Accurate,Quality Lenses

      Cons:

      Comments:

      I'm a beginner and heard about Agena's EP's at Cloudy Nights. This wide angle piece is a great value.

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

      This review was provided courtesy of AgenaAstro.com

    15. Guest

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      Review by pvaz of Portugal.
      1260230400
      Dec 7, 2009

      5.0 Great quality at a good price.

      Pros:

      Compact,Strong Construction,Accurate,Quality Lenses

      Cons:

      Comments:

      This is a great eyepiece. It's very solid construction, excellent light scatter control, a good wide field and good eye relief without any kidney beans or any other nasty effects. Only minor problem it has is when used in Newtonian fast (under f/6) scopes. Then you see a bit of coma on the edge of the FOV extending for 10%. It's not much and I find it acceptable, specially if you consider that to get read of this you need EPs that cost 5 to 10 times as much. It's very comfortable to use. It's one of those EPs that seam to "get out of the way" between you and the target you're observing. If you have an f/6+ scope you'll be 100% satisfied. With a f/6- they still perform great and are a great value for you money.

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

      This review was provided courtesy of AgenaAstro.com

    16. dmbryan

      dmbryan New Member

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      1248072120
      Jul 19, 2009

      4.0 Solid eyepiece for the money

      Pros:

      Well built, huge field of view, very bright, easy to see DSO's

      Cons:

      edges out of focus in 4.5 reflector.

      Comments:

      I bought this eyepice for use in an 80 mm refractor and starblast 4.5 reflector. The eyepiece is well built and feels solid. Filters thread onto it very well. The eyepiece has great relief and huge field of view. Viewing through it causes no eyestrain at all. In the 80 mm refractor the images are crisp all the way to the edge. In the 4.5 reflector the images are out of focus at the edges. It still focuses crisply in the middle, you just loose a little on the edges( this is the only minimal drawback I found). Overall I love this eyepiece and would recommend it to a friend.

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

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      Review by Starviewer of Missoula MT.
      1243555200
      May 28, 2009

      4.0 SWA eyepiece

      Pros:

      Accurate,Strong Construction,Quality Lenses

      Cons:

      I cannot find any major

      Comments:

      I am using this eyepiece in a Nexstar 6'' scope, and it is one of my favorite oculars. I am an optician, and have been an amateur astronomer for a long time! This ocular is very sharp, showing 6 of Saturn's moons at about 75x.

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

      This review was provided courtesy of AgenaAstro.com

    18. TransPecosDob

      TransPecosDob New Member

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      Review by rekterx of Alpine, TX.
      1243382400
      May 26, 2009

      5.0 Tremendous Value

      Pros:

      Accurate,Strong Construction,Compact,Quality Lenses

      Cons:

      Comments:

      I use this in my Celestron Omni XLT 102 and it is a match made in heaven. I get a reasonably wide view in an 1.25 diagonal that is very clear to almost the edge of the field. I plan to get more of these. Great all round eyepiece.

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

      This review was provided courtesy of AgenaAstro.com

    19. Guest

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      Review by mhuston6 of Florida.
      1227398400
      Nov 22, 2008

      5.0 Agena AstroProducts SWA 20mm

      Pros:

      Clear bolt case,No false color,Parfocal

      Cons:

      End cap won't fit in case

      Comments:

      I bought this Agena 70* 20mm used but it was in new condition! The color corrective coatings are very good! The eye relief is great! Since I do a lot of imaging and viewing, parfocal is a must and this has that! So I can say by using this for the past 2 months, I am very pleased with the views!

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

      This review was provided courtesy of AgenaAstro.com

    20. AstroGuy1

      AstroGuy1 New Member

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      Review by nam2525 of Washington.
      1227139200
      Nov 19, 2008

      5.0 Excellent quality and stunning views

      Pros:

      Excellent quality,Great performance,Large AFOV

      Cons:

      Slight off-axis color,For medium to slow scopes

      Comments:

      I got the Agena Astroproducts SWA 20mm eyepiece to compare directly against the William Optics SWAN 20mm. I sold the SWANs and kept the Agena Astro eyepieces and here is why:

      The Agena had truly blackened lens edges and very little stray light from the eyepiece barrel. The coatings were well applied, and the quality was excellent. It came with a bolt case and had a black, reversible barrel which comes in handy for binoviewer use in my Burgess binos.

      The Agenas do well for both low power viewing and high power lunar and planetary observing. There is some lateral color when you try to view something like Saturn near the edge of the field, but this is expected in a wide angle eyepiece...some sacrifices had to be made. However, as long as you can keep the object fairly centered in the field of view, there is no lateral color at all, and the views are excellent. There is some field curvature present, but in my F8 scope I did not find this annoying or even really noticeable at all. However, these eyepieces are not really for a fast scope, and in the ST80 which is an F5 scope, the stars turned into lines starting at about half-way out from center of the field of view. For a fast scope, stick with a plossl or some other eyepiece with a flat field.

      To sum up, these eyepieces are of excellent quality and provide wonderful views in medium to slow scopes. Highly Recommended!!!

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

      This review was provided courtesy of AgenaAstro.com

    21. mhuston6

      mhuston6 New Member

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      1183230720
      Jun 30, 2007

      5.0 Agena AstroProducts SWA 20mm

      Pros:

      No false color; parfocal; clear bolt case!

      Cons:

      The tops lens cap won't fit inside the bolt case, but it's nice to have!!

      Comments:

      I bought this Agena 70* 20mm used but it was in new condition! The color corrective coatings are very good! The eye relief is great! Since I do a lot of imaging and viewing, parfocal is a must and this has that! So I can say by using this for the past 2 months, I am very pleased with the views! It comes with a nice clear bolt case which makes it very easy to see the size of the EP!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No
    22. nam2525

      nam2525 New Member

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      1183224300
      Jun 30, 2007

      5.0 Excellent quality and stunning views

      Pros:

      Large AFOV, excellent quality, great performance

      Cons:

      Slight off-axis color. Really intended for medium to slow scopes

      Comments:

      I got the Agena Astroproducts SWA 20mm eyepiece to compare directly against the William Optics SWAN 20mm. I sold the SWANs (which cost about $80 each) and kept the Agena Astro eyepieces and here is why:

      The Agena had truly blackened lens edges and very little stray light from the eyepiece barrel. The coatings were well applied, and the quality was excellent. It came with a bolt case and had a black, reversible barrel which comes in handy for binoviewer use in my Burgess binos. To see all the things wrong with the William Optics SWAN, just see my review here on Astronomy Ratings and also on Cloudy Nights.

      The Agenas do well for both low power viewing and high power lunar and planetary observing. Unlike what was stated in another review here, there is some lateral color when you try to view something like Saturn near the edge of the field, but this is expected in a wide angle eyepiece...some sacrifices had to be made. However, as long as you can keep the object fairly centered in the field of view, there is no lateral color at all, and the views are excellent. There is some field curvature present, but in my F8 scope I did not find this annoying or even really noticeable at all. However, these eyepieces are not really for a fast scope, and in the ST80 which is an F5 scope, the stars turned into lines starting at about half-way out from center of the field of view. For a fast scope, stick with a plossl or some other eyepiece with a flat field.

      To sum up, these eyepieces are of excellent quality and provide wonderful views in medium to slow scopes. Highly Recommended!!!

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

      Apparent Field of View 70°
      Barrel Size 1.25" (31.7mm)
      Bolt Case Included Yes - Free Agena Eyepiece Container
      Bolt Case Size Agena 42x80mm
      Coatings Fully Broadband Multi-Coated
      Height (with Eye Guard) 2.73" (69.3mm)
      Height (without Eye Guard) 2.41" (61.1mm)
      Max Width 1.39" (35.2mm)
      End Caps 2
      Eye Relief by Design 16mm
      Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6)
      Focal Length 20mm
      Lens Elements 5
      Lens Groups 4
      Rubber Eye Guard Yes
      Blackened Lens Edges Yes
      Manufacturer Agena AstroProducts
      Eyepiece Focal Length 15.1mm - 20mm
      Eyepiece Field of View 61 - 70 degrees
      Eyepiece Series Agena SWA
      Barrel Type With safety undercut
      Parfocal No
      Eyepiece Weight 4.20oz (119.07g)