William Optics 1.25" Swan Series Eyepiece - 20mm

Description

William Optics 1.25" Swan Series Eyepiece - 20mm. Condition is "New". Shipped with USPS First Class.
Super Wide FOV
Outstanding super-wide field of view: 72 deg. FOV
Fully Multicoated lenses for excellent transmittance.
Reduced chromatic aberration.
Improved contrast compared to similar EPs.
Great Contrast
Internally fully blackened (lens edges and internal spacers).
No flaring or ghosting on high-contrast objects.
Parfocal.
Light and Easy
Soft rubber eyecup.
Long eye-relief: 17mm.
No internal reflections, kidney beaning or other distracting distortions.
Terrific Fit and Finish
High-resistance anodized black barrel.
Smooth design for no hook up in your focuser.
Threaded for use with 1.25" filters.
Features
:
SVBONY super-wide angle 1.25" zoom eyepiece.
The zoom eyepiece allows you to change magnification power without swapping out eyepieces.
5-Elements / 3-groups made of high index glass deliver sharp, high contrast vistas.
A simple twist of the zoom eyepiece housing changes the focal length from 30mm to 10mm, providing a variety of viewing magnification powers.
Exceptionally long 17mm-18.5mm eye relief range allows eyeglass wearers to enjoy the entire field of view without needing to remove their glasses.
Sleek black barrel with safety undercut to reduce the possibility of the eyepiece slipping out of the focuser or diagonal.
Blackened lens edges, anti-reflection threads for maximum contrast.
Package Includes
SV170 Black 1.25in 10-30mm zoom eyepiece
Two Rubber Dust cover
Mirror Cloth
Model
SV135
SV170
SV171
Focal length
7-21mm
10-30mm
8-24mm
Eye Relief
18mm - 16.3mm
17-18.5mm
18-19.5mm
Zoon Type
Linear
Lens structure
6PCS / 4group
5 -Elements/-3Groups
7-Elements/4-Groups
Interpupillary Dist.
15mm
Barrel Size
1.25"
1.25"
1.25"
Field of view
57° ~ 40°
33°-51°
38°-56°
Coatings
Fully Multi-Coated-Green
Fully Multi-Coated
Fully Multi-Coated
Rubber Eye Guard
Yes
Blackened Lens Edges
Yes
Yes
Barrel Safety Recess
Yes
Yes
Eyecups Meterial
Metal
Metal
Metal
Eyecups
Twist-Up
Twist-Up
Thread Size
M28.5*0.6
M28.5 x 0.6
M28.5 x 0.6
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