Engineered to Al Nagler's uncompromising standards but at an entry-level price, the long-focal length Tele Vue Plossl 20mm Eyepiece produces a relatively low magnification on most OTAs for both near and deep-sky observations.
It is made using diffraction-limiting high-index glass lenses in a 4-element/2-group configuration to keep light on-axis and reduce astigmatism and edge-aberrations across its entire 50° apparent field of view. Fully multi-coated optics, blackened lens elements, and anti-reflection threads complement the optical components to improve contrast and light transmission, while limiting its loss. Its generous 14mm eye relief allows users the room to back off slightly from the eyecup for a more comfortable viewing experience with a reduced risk of accidental contact with the eyepiece lens which can cause vibrations and interfere with views. Ideal for fast-focal ratio OTAs, the eyepiece features a standard 1.25" barrel to be compatible with the most popular size of focuser and accessories, with a convenient fold-down rubber eyecup. This model of the Plossl series is parfocal with all Tele Vue Group 'B' eyepieces, allowing you to change compatible eyepieces without having to refocus — saving time and limiting vibrations.
 
Key Features
20mm Focal Length
50° Apparent Field of View
1.25" Diameter Barrel
Ideal for Fast Focal Ratio OTAs
Diffraction-Limiting High-Index Glass
Multi-Coated Optics with Blackened Edges
Parfocal with All Group "B" Eyepieces
Fold-Down Rubber Eyecup
 
20-mm
Model #
EAP-20.0
Focal Length (mm)
20
Barrel Size (in.)
1¼"
Apparent Field of View (deg.)
50
Eye Relief (mm)
14
Weight (lb / oz)
0.19 / 3.0
Field Stop (mm)
17.1