The Swan eyepieces are super wide angle designs with 72-degree 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 multi-coated 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, both day and night!
The William Optics SWAN 40 mm Eyepiece has 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.
This 4-element super-wide angle 40 mm SWAN EP's panoramic views at 72 deg. F.O.V. will leave you speechless!
William Optics 40 mm SWAN Eyepiece Features
- Fully Multicoated lenses for excellent transmittance..
- Reduced chromatic aberration.
- Improved sharpness and contrast throughout the field.
- No internal reflections, kidney beaning, pin-cushion or other distortions.
- Smooth design for no hook up in your focuser.
- Threaded for 2" filter usage.
- Rubber grip ring for safe, comfortable handling.