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Agena 1.25" Starguider Dual ED Eyepiece - 18mm

4.8 (13 Reviews) Read Reviews Write Review
Brand Agena AstroProducts
Part Number E-AG-SGED18
Availability available

Product Info

Manufacturer Description

With a true flat field and two high quality ED glass elements of different glass types, the new Agena StarGuider Dual ED eyepieces are characterized by a significantly high contrast image. These 1.25" fully multicoated (FMC) eyepieces give maximum detail and definition across the entire 60 degree field of view (FOV). This feature is especially useful for telescopes without tracking capability where the object drifts across the field of view during observation. A great value, these eyepieces are exceptional at nearly eliminating lateral color aberration and light scatter often associated with more expensive eyepieces that are better suited for deep space objects.

The eyepieces are parfocal, minimizing the amount of refocusing needed when switching from eyepiece to eyepiece within the series.

Agena Dual ED Eyepieces vs. More Expensive Eyepieces:

Premium (and costly!) eyepieces that have similar wide fields of view need many exotic glass elements to achieve that wide field of view - as many as 9 lenses or more. More lenses mean more cost and more glass, which attenuates the amount of light you see. That also means there are more air-to-glass surfaces that can scatter light - reducing contrast and sometimes causing multiple reflections (ghosting) when viewing very bright objects such as the Moon and planets. Extra lenses can also mean compromises in the overall design that can often lead to other issues.

One such issue of all that glass is lateral color aberration. This results when different wavelengths (colors) of light pass through the eyepieces focal plane at different points and appear as a cloud of false color around bright objects. Another issue is light scatter seen as a distracting halo or glow around bright objects. This can also reduce contrast. Light scatter and lateral color are rarely seen in very wide field eyepieces when observing faint deep sky objects, but they become very apparent when viewing lunar, planetary, and double star objects. These objects don't need an extra-wide field of view to see small details and subtle contrast differences. Our 60 degree eyepieces provide high contrast, no scattered light, and the highest possible definition.

Agena Eyepieces - Rooted in Solid Design:

Orthoscopic and Plossl eyepieces have traditionally been the designs of choice for lunar, planetary, and binary star/star cluster observations. Their low number of lenses (typically four) and air-to-glass surfaces give better contrast and definition than the more exotic extra wide field eyepieces. A high quality orthoscopic or Plossl eyepiece on a good telescope gives views of Mars, Jupiter, and Saturn that can be breathtaking. But even these designs can be improved upon for lunar and planetary use.

Long Eye Relief - Up To 20mm!

Agena's StarGuider Dual ED eyepieces are the first long eye relief eyepieces with a comfortably wide field for planetary observing that also give the sharpness, contrast, and lack of lateral color and light scatter of the best orthoscopic and Plossl designs. What they don't have is the limited eye relief and restricted fields. Our eyepiece eye relief averages around 18mm and is as much as 20mm in the 25mm focal length model. Even the 5mm eyepiece has almost 16mm of eye relief! Experienced observers will truly appreciate such generous eye relief at significant magnifications.

The nicely machined body is rubberized and scalloped grooves around the circumference at the top provide a secure grip in all conditions.

Sharpness, Great Contrast and Flat Field of View:

With up to six lens elements in this unique design, these eyepieces are fully internally baffled and all internal spacers have antireflection microbaffles on their edges with flat black anodizing to reduce reflections. The field stop also has microbaffles in its edge to reduce off-axis flaring and produce a sharply delineated field edge. Every air to glass surface is broadband multicoated for peak light transmission and outstanding contrast on subtle lunar and planetary detail. The lens edges are blackened to eliminate internal reflections.

The eyepieces have a twist-up eyecup that can be raised or lowered as much as 11mm to provide the eye relief you find most comfortable. Spherical aberration of the exit pupil is well controlled, so there are no serious blackouts or kidney-bean effects if you move your eye slightly off the axis. Dust covers are provided for both ends of each eyepiece. A groove is machined into the nose piece barrel to ensure the eyepiece is less likely to fall out of the diagonal or focuser if the capture screw becomes accidentally loose.

Technical data:

  • Focal length: Available in focal lengths of 5mm, 8mm, 12mm, 15mm, 18mm and 25mm
  • 1.25" with filter thread
  • Field of view: 60°
  • Fully multi-coated on each glass/air surface

Reviews

4.8 (Based on 13 Reviews) 100% of reviewers recommended this product.
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    1. Guest

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      Review by Terry S.
      1550093532
      Feb 13, 2019

      5.0 Extra Nice WA Eyepiece

      Pros:

      Cons:

      Comments:

      The 18mm, like all in this set, is a sharp, comfortable eyepiece. Excellent in all respects and highly recommended.

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

      This review was provided courtesy of AgenaAstro.com

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      Review by Irv S.
      1543856386
      Dec 3, 2018

      5.0 good eyepiece

      Pros:

      Cons:

      Comments:

      good optics, and nice wide FOV. like the rubber coatings. Fees like quality construction. would buy again.

      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 Walter L.
      1537391963
      Sep 19, 2018

      5.0 Astronomy nut for 55 years.

      Pros:

      Cons:

      Comments:

      I had bought Celestron LX eyepieces for my small scope. A Celestron 6”. They were nice, but suffered from blackouts if you’re eye position wasn’t perfect. These eyepieces have no optical quirks that I can detect. Great eye relief and pinpoint stars to the edge of field on a f/10 scope.

      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 Jonathan B.
      1530733401
      Jul 4, 2018

      5.0 Solid lower-mid range eyepiece

      Pros:

      Cons:

      Comments:

      Great eye relief and decently-wide field of view. Noticeable step up from a plossl without breaking the bank.

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

      This review was provided courtesy of AgenaAstro.com

    5. Ronald Zincone

      Ronald Zincone New Member

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      Review by Ronnie Z.
      1502548315
      Aug 12, 2017

      5.0 Agena Starguider eyepiece

      Pros:

      Cons:

      Comments:

      A nice wide-field, 60 deg, but not too wide FOV....just perfect. Nice coatings and great contrast, sharpness to the edge, no internal reflections, just a great piece of glass as is the entire set!!!

      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 Daniel P.
      1499367772
      Jul 6, 2017

      4.0 Hard to find a good wide field 18mm

      Pros:

      Cons:

      Comments:

      I like the 5mm version of this eyepiece very much. Like the 5mm, this 18mm is well constructed. It gives very good views in my f/10 refractor. In f/5 and f/6 reflectors the center 80% of the field is sharp, but the outer 10% looks curved and the focus is very soft. There's also a slight blur ring just inside the field stop. Overall it's a nice eyepiece, better than most 18mm wide fields I've tried, but it's not perfect.

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

      This review was provided courtesy of AgenaAstro.com

    7. Guest

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      Review by Curtis A.
      1499223881
      Jul 4, 2017

      4.0 Excellent Value, Comfortable Views

      Pros:

      Cons:

      Comments:

      I've really enjoyed using this eyepiece so far. For my f4 Starblast 4.5, the 17-18mm range, both barlowed and without, has always provided consistently good views, and since purchasing it, this is the eyepiece I've been coming back to most. The Starguider provides a nice middle of the road FOV, comfortable eye relief, and in the Starblast, gives great views of larger DSOs. In my f6 Z8 dob, planets have minimal visible distortion across the field, as well. Details with the Starguider 18mm are sharp on just about any given night. Quality construction and seemingly a great value, especially compared to other EPs

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

      This review was provided courtesy of AgenaAstro.com

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      Review by JOSEPH D.
      1491993424
      Apr 12, 2017

      5.0 Best for the price

      Pros:

      Cons:

      Comments:

      The Agena Starguider Dual ED eyepiece are the best available for the price, i believe. They have a wide, flat field and good eye relief. They are very comfortable to use. I have all rom the 3.5mm to the 18mm. You might pay a lot more and get an eyepiece that is better. But it won't be that much better!

      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 N2KEN of Brooklyn, NY.
      1453680000
      Jan 24, 2016

      5.0 Great views with Binoviewer

      Pros:

      Quality Lenses,Accurate,Easy to Use,Strong Construction,Very Good Contrast

      Cons:

      Comments:

      These are very well designed and constructed eyepieces. They have a solid feel and the twist-up rubber eyecup is very smooth. I bought a pair for use in my TeleVue BinoVue and the 60 degree field of view is perfect. Views of clusters, the moon and Jupiter were sharp and clear across the entire field with my C6 sct.

      When I first opened the eyepieces I thought they might be a bit wide at the top for comfortable bino use. No problem. They are comfortable to use, have nice eye relief, and nicely matched with each other. The rubberized body provides a comfortable grip when handling them. The views were nicer with these 18mm in the bino than a single 15 or 9mm. Jupiter and four moons filled about 3/4 of the field. But, the view was sharp and clear with the cloud bands distinct. The contrast and clarity is very good. Stars were pinpoint sharp across the field and the moon's surface showed crisp detail. These will be getting a lot of use. I tried a single eyepiece for comparison and it was quite impressive.

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

      This review was provided courtesy of AgenaAstro.com

    10. Guest

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      Review by telescope tom of Tucson.
      1444521600
      Oct 10, 2015

      4.0 Really nice for the price.

      Pros:

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

      Cons:

      Comments:

      Really works well for the price even in f/5 scopes.

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

      This review was provided courtesy of AgenaAstro.com

    11. Guest

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      Review by jscarborough55 of Texas.
      1426204800
      Mar 12, 2015

      5.0 Excellent eyepiece

      Pros:

      Quality Lenses,Easy to Use

      Cons:

      None

      Comments:

      Quality eyepiece. Great eye relief. One can feel the quality construction by just holding it. Agena Astro service second to none.

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

      This review was provided courtesy of AgenaAstro.com

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      Review by jscarborough55 of Texas.
      1426118400
      Mar 11, 2015

      5.0 Excellent eyepiece

      Pros:

      Strong Construction

      Cons:

      None

      Comments:

      Excellent eyepiece. Great value. Excellent Agena Astro service.

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

      This review was provided courtesy of AgenaAstro.com

    13. Guest

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      Review by HarryTraver of Marine City, MI.
      1410220800
      Sep 8, 2014

      5.0 Superb eyepiece

      Pros:

      Quality Lenses,Excellent contrast,Excellent Fov,Excellent resolution

      Cons:

      Heavy

      Comments:

      I was intent on updating and retiring my old working sets of eyepieces and create a unified set that would be more versatile. These would have to have a high degree of resolution for binaries, high contrast for planetary work, and a comfortably wide field for deep sky work at all magnifications.

      After months of reading and research, I actually stumbled onto Agena's impressive lineup of oculars. The Agena ED oculars are extremely flat across their field with excellent color correction. The eye lens is incredibly large. No pinholes here even at 5mm!

      The apparent field of view is spacious enough for deep sky with excellent resolution for binary star busting. Their high contrast is great for bringing out subtle deep sky object and planetary detail. All this is accomplished with just 5 lenses in 4 groups. They do not rob me of precious light as more complex designs would.

      The feel and build quality is simply first-class. I bought the entire ED series and am delighted in their performance with my 3" & 4" Unitrons and 6" AVX refractor. These and my Agena BSTs are a tremendous value.

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

      This review was provided courtesy of AgenaAstro.com

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      Specifications

      Apparent Field of View 60°
      Barrel Size 1.25" (31.7mm)
      Bolt Case Included Yes - Free Agena Eyepiece Container
      Bolt Case Size Agena 52x80mm
      Coatings Fully Multi-Coated
      End Caps 2
      Eye Relief by Design 18mm
      Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6)
      Focal Length 18mm
      Lens Elements 5
      Lens Groups 4
      Rubber Eye Guard Yes (Twist-Up Eyecup)
      Blackened Lens Edges Yes
      Manufacturer Agena AstroProducts
      Eyepiece Focal Length 15.1mm - 20mm
      Eyepiece Field of View 51 - 60 degrees
      Eyepiece Series Agena Dual ED
      Barrel Type With safety undercut
      Eyepiece Weight 5.50oz (155.92g)