The Swan eyepieces are super wide angle designs with a 72° apparent
field of view. They use simple but sophisticated five-lens optical
systems for generally higher contrast than the more complicated optical
designs used in some other super wide angle eyepieces that use up to
eight lenses. All lenses are fully multicoated for high light
transmission. Lens edges and internal field stops are blackened to
reduce internal reflections and improve contrast. The eyepiece rubber
grip ring is useful for safer handling of the heavier 2” eyepieces in
cold weather when wearing gloves. The eyepieces have soft roll down
rubber eyecups for eyeglass use. They can be used for all types of
observing, with all telescope types, but they are recommended for use
with focal ratios up to f/6 and above. Dust caps are provided for both
ends of each eyepiece. A soft protective drawstring-equipped velvet
storage bag is standard equipment with each.
This 5-element super-wide angle 20mm SWAN EP's panoramic views at 72 deg. FOV will leave you speechless!
It offers the perfect compromise between quality, cost, eye-relief and edge sharpness.Ideal with SCT and refractor telescopes.
Perfect Match with William Optics Telescopes
• Outstanding super-wide field of view: 72 deg. FOV
• Fully Multicoated lenses for excellent transmittance.
• Outstanding chromatic aberration correction.
• Excellent contrast and light throughput for sharp viewing.
Great Contrast
• Internally fully blackened (lens edges and internal spacers).
• No internal reflections.
• No flaring or ghosting on high-contrast objects.
• Parfocal.
Light and Easy
• Soft rubber eyecup
• Long eye-relief: 17 mm
• No internal reflections, kidney bean effect
Terrific Fit and Finish
• High-resistance anodized black barrel.
• Smooth design for no hook up in your focuser.
• Threaded for 1.25” filters.
| Model | SWAN 20 |
| Focal Length | 20mm |
| Lens Structure (#Elements/#Groups) | 5/4 |
| Field of View | 72° |
| Eye Relief | 17mm |
| Barrel | 1.25" |
| Coating | FMC
|
| Parfocal | Yes |
| Weight | 100g |
If you have any comments or reviews you'd like to share with us, please email us. Thank you. |
