Agena 1.25" Starguider Dual ED Eyepiece - 8mm
Brand | Agena AstroProducts |
Part Number | E-AG-SGED8 |
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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Jan 20, 2019
Great eyepiece for the money!
Pros: Cons: Comments:I just got into astronomy and was looking to upgrade my eyepieces. I was willing to pay about triple the money that these cost for an eyepiece. These were recommended to me on a message board, so I decided to give them a try, and I’m so glad that I did! I bought the 8mm and 5mm and love them both! I was able to buy both for what I would of paid for one of the other brands. I have gotten amazing views out of these with just a beginner telescope! I definitely recommend these!!
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Jul 8, 2018Starguider Ed Eyepieces Rock
Pros: Cons: Comments:I have 3 of these eyepieces and believe these are the best value in excellent quality / moderate FOV with a very flat field, available on the market today.The FOV is perfect, not stretched to much, very flat with pinpoint stars to the edge.The true color rendition is very good, very little or no internal reflections. I have very expensive Naglers in my special eyepiece case but i find i am using these just as often and am very pleased.The twist up eyepiece cup is a very nice feature too. Plus, you get free shipping, and most items are here in two days. I live in Georgia. Not bad for free shipping. Agena is rapidly becoming my favorite vendor!
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Apr 4, 2018Agena Starguider Dual ED Lens Eyepiece Series
Pros: Cons: Comments:Hi, I wanted to take a moment to comment on the Starguider Dual ED Lenses. I was quite surprised how
Bottom Line: Would you recommend this item? Yes
great these eyepieces are considering their cost. They just really got my attention, I noticed & said WOW!
What a surprise! They are BRIGHT! Very Clear! Defiantly an overlooked eyepiece series.
I have the 5mm up to 18mm. They work very well on my 80mm ED Telescope & on the rest on my scopes too.
Less lenses in the eyepiece lets more light come through, and with the ED lenses they are very clear.
I have many very expensive eyepieces but these cheaper ones are nothing to scoff at.
I have found lots of different eyepieces in my kit keeps it interesting. Lots of different views makes it fun.
I even use them on my 50mm RACI Finder scope. The twist up eye cups are simple & smooth but the
threads on the twist up eye cup could of been a little better, that's where they cut the costs & spent it on the lenses. Don't get me wrong they work great. I just try to give honest opinions & view points.
Good luck!This review was provided courtesy of AgenaAstro.com
Sep 12, 2017Agena Affordable Quality
Pros: Cons: Comments:Another excellent quality eyepiece added to my collection. My main eyepiece is the Agena 12mm and the 8 gives me the same high quality views when conditions are good and the target just needs a bit more magnification. Looking forward to the next purchase.
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 28, 2017Great piece of glass!
Pros: Cons: Comments:As in all the rest of the Agena Starguider series of eyepieces, just superb! Really nice contrast, sharp to the edge and a perfect 62 degree FOV.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Apr 10, 2017Good eyepiece
Pros: Cons: Comments:At this price point, this eyepiece delivers an excellent image in both of my scopes, a refractor and a reflector. I use it for better detail on Jupiter and Saturn and split doubles with it. When the seeing is good, images are sharp and clear. I own several others in this line and I am happy with all of them.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Jun 9, 2016It's a Keeper
Pros:Quality Lenses,Easy to Use,Accurate,Strong Construction,Compact,Lightweight
Cons: Comments:I picked up this as a grab and go for my smaller 80mm and 127mm scopes but thought I'd give it a try in my 14" f/4.7. I compared it with a Vixen 8mm LVW at 209X. Objects included the Moon, Jupiter, Mars and Saturn along with several open clusters. I was hard pressed to find any significant difference. There were some internal reflections visible on Jupiter, but other than the slightly narrower field in the Starguider, there was nothing significant.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Jul 7, 2015Nice EP, great view
Pros:Quality Lenses,Strong Construction,Easy to Use
Cons: Comments:Provides nice view of saturn with my Nexstar 90GT at about 110x. Details were visible including the Cassini Division. Moon details are better than the stock 10mm EP. I was also able to view the sun with proper filter of course. Eye needs to be on proper position to prevent blackouts but easy enough to do.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Jun 27, 2015Solid for the price
Pros: Cons: Comments:Good flat FOV. I like the screw style eyecup for putting your eye in perfect spot. Have treated lens very well but have a couple dust specs between seals.
Bottom Line: Would you recommend this item? NoThis 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 16.5mm Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6) Focal Length 8mm Lens Elements 5 Lens Groups 3 Rubber Eye Guard Yes (Twist-Up Eyecup) Blackened Lens Edges Yes Manufacturer Agena AstroProducts Eyepiece Focal Length 5.1mm - 10mm Eyepiece Field of View 51 - 60 degrees Eyepiece Series Agena Dual ED Barrel Type With safety undercut Eyepiece Weight 5.70oz (161.59g)