Agena 1.25" Wide Angle High Definition Eyepiece - 2.5mm
Outstanding Planetary and Lunar Eyepieces
Primarily made for planetary observation, these 1.25" fully multicoated (FMC) eyepieces give maximum detail and definition across the entire 58 degree field of view (FOV). 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.
Each eyepiece has 5 lens elements in 3 groups - with the exception of the 20mm eyepiece which has 4 groups.
Agena WA HD Planetary Eyepieces vs. More Expensive UWA 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 that appears 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. Our 58 degree eyepieces provide high contrast, no scattered light, and the highest possible definition.
Long Eye Relief - Up To 20mm!
Our eyepiece eye relief averages around 15mm and is as much as 20mm in the 25mm focal length model. Even the 2.5mm eyepiece has almost 17mm of eye relief! Experienced observers will truly appreciate such generous eye relief at significant magnifications.
Excellent Fit and Finish:
These eyepieces are fully internally baffled and all internal spacers have antireflection microbaffles on their edges with flat black anodizing to reduce reflections. 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.
Each eyepiece has a flexible rubber fold-down eyeguard. 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.
Real World Results:
In an independent test the 4mm Agena WA HD planetary eyepiece, for example, performed visibly better than a 2x Barlowed 8mm top-tier Plossl costing about $100 - with an additional 6 degrees FOV. Another field test showed that our planetary eyepieces kept a better, more natural coloring of Jupiter across the entire field of view than a much more expensive brand at the same focal length. And the longer focal length eyepieces still provided excellent edge performance and true flat field even when used in a fast (f/5) scope. Such results are truly amazing, considering the low price of the Agena WA HD Planetary eyepieces.
|Apparent Field of View||58°|
|Barrel Size||1.25" (31.7mm)|
|Bolt Case Included||Discontinued Item|
|Bolt Case Size||Agena 52x80mm|
|Eye Relief by Design||16.5mm|
|Filter Threads||Standard 1.25" Filter Thread (M28.5 x 0.6)|
|Rubber Eye Guard||Yes|
|Blackened Lens Edges||Yes|
|Eyepiece Focal Length||5mm and Under|
|Eyepiece Field of View||51 - 60 degrees|
|Eyepiece Series||Agena WA HD|
|Barrel Type||With safety undercut|
|Eyepiece Weight||5.90oz (167.26g)|