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Agena 1.25" Starguider Dual ED Eyepiece - 18mm
| Brand | Agena AstroProducts |
| Part Number | E-AG-SGED18 |
| Availability | available |
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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
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Feb 13, 2019
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? YesThis review was provided courtesy of AgenaAstro.com
Sep 19, 2018Astronomy 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? YesThis review was provided courtesy of AgenaAstro.com
Jul 4, 2018Solid 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? YesThis review was provided courtesy of AgenaAstro.com
Ronald Zincone New Member
- Skill Level
- Unknown
- Time with Product
- Unknown
- User Notes:
- Review by Ronnie Z.
Aug 12, 2017Agena 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? YesThis review was provided courtesy of AgenaAstro.com
Jul 6, 2017Hard 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? YesThis review was provided courtesy of AgenaAstro.com
Jul 4, 2017Excellent 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? YesThis review was provided courtesy of AgenaAstro.com
Apr 12, 2017Best 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? YesThis review was provided courtesy of AgenaAstro.com
Jan 24, 2016Great 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.
Bottom Line: Would you recommend this item? Yes
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.This review was provided courtesy of AgenaAstro.com
Oct 10, 2015Really 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? YesThis review was provided courtesy of AgenaAstro.com
Mar 12, 2015Excellent 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? YesThis review was provided courtesy of AgenaAstro.com
Sep 8, 2014Superb 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.
Bottom Line: Would you recommend this item? Yes
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.This review was provided courtesy of AgenaAstro.com
Sort bySpecifications
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)
