ED stands for "Extra-Low Dispersion". These eyepieces use optical glass in which two of the lens elements are crafted from ED glass which is a special grade of glass that provides much superior refractive properties as compared to standard optical glass. This results in much better color correction. ED glass is often the type used in many expensive camera lenses and high-end refractor telescopes costing thousands of dollars.
Our ED-series eyepieces are available in a 1.25" barrel in 10 focal lengths (2.3, 3.8, 5.2, 7.5, 9.5, 12.5, 14, 18, 21 and 25mm). They feature a six-element lens design that provides significantly reduced chromatic aberration, high resolution and excellent sharpness without compromising image brightness. Their long 20mm eye relief means that even eyeglass wearers can take in the full 55-degree apparent wide field of view (AFOV).
All ED-series eyepieces are fully broadband multi-coated for maximum image brightness. Lens edges are blackened throughout for improved contrast. The eyepiece housing is precision machined from aluminum and clear-anodized to a lustrous finish. A rubber traction ring ensures a secure grip and a rubber eyeguard helps position your eye to block out stray light. The chrome barrel features a setscrew recess for added security. All eyepieces are parfocal and are threaded to accept standard 1.25" filters. Each eyepiece comes in a bolt case with two plastic end caps. Compare these with the ED eyepieces sold in very similar focal lengths by two of the "Big-3" telescope companies and you'll realize the savings we offer.
Oct 2, 2012
Best eye glass wearer performer for pricePros:
Good Edges,Bang On Eye Relief,Quality Lenses,AccurateCons:
Slightly Hard To AlignComments:
With 6 elements this EP nails it. Good color, contrast, eye relief. 55 degree is just fine and crisp. Bang on design. Sun fills the scope in f/6 8" dob. Clearly superior to Celestron X-Cel. Next step up would be a Baader Hyperion.
This review was provided courtesy of AgenaAstro.comMay 5, 2010
Couldn't Use ItPros:
Quality Lenses,Strong ConstructionCons:
Difficult to Use,Unstable,Heavy,Poor Lens Quality,Difficult To FocusComments:
When I took this eyepiece out of the box, I was awed by how large and heavy it was. The first thing that came to my mind was... this is no EP for small telescopes. When I used it the first time, the first thing that I immediately noticed was that the planet or star was there, and then it wasn't, and then it was there, and then it wasn't. It was at that point that I realized that what I was seeing was what is often referred to as the "kidney bean effect." I call it the "rolling black-out effect." The image itself was sharp, but keeping it in view was difficult and very annoying. I tried using it again and again, thinking it was just me not being used to it. But it never got any better. This is why I checked the block beside "Poor Lens Quality." Even though the object was sharp, something about the lens made it difficult to keep the object in view. I finally stopped using the eyepiece altogether.
This review was provided courtesy of AgenaAstro.comMay 27, 2009
18mm 1.25" ED eyepiecePros:
Strong Construction,Quality LensesCons: Comments:
This is not my first purchase of the ED type lens. It really excels in planetary and lunar viewing. I also have a complete set of Meade 4000's and three TeleVue Radiams
This review was provided courtesy of AgenaAstro.com
AstroGuy1 New Member
- Skill Level
- Time with Product
Nov 19, 2008
- User Notes:
- Review by APOLLO13 of New Mexico.
AGENA 18MM EDPros:
Detailed views,Very sharp edge to edgeCons:
Wow, had this eyepiece out tonite in a 9.25xlt f/10. And I am very impressed. The sharpness edge to edge, no false color, very good eye relief, coatings are very good, no ghosting or flares at all. I compared it to a TV 20mm and its very close to call. DSO's m101, m42 and Saturn were the objects for the nights review. All objects were cleanly seen and framed very well. And for half the price, it's a keeper for me. Amazing how this eyepiece is very well built and quality just looks great.
This review was provided courtesy of AgenaAstro.comSort by
Apparent Field of View 55° Barrel Size 1.25" (31.7mm) Bolt Case Included Yes - Manufacturer Supplied Bolt Case Size - Coatings Fully Broadband Multi-Coated Height (with Eye Guard) 4.1" (105mm) End Caps 2 Eye Relief by Design 20mm Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6) Focal Length 18mm Lens Elements 6 Rubber Eye Guard Yes Blackened Lens Edges Yes Manufacturer Agena AstroProducts Eyepiece Focal Length 15.1mm - 20mm Eyepiece Field of View 51 - 60 degrees Eyepiece Series Agena ED Barrel Type With safety undercut Eyepiece Weight 7oz (198.45g)