William Optics SWAN Eyepiece

William Optics SWAN Eyepiece


In stock - Shipped 1-2 working days.

Model:  WOswan-1
Part Number:  E-SWA09
Brand:  William Optics

William Optics Swan eyepieces are super-wide-angle designs with 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 SWA 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 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 are remarkably good all-round eyepieces when used with telescopes with focal ratios up to f/6 and above.

Technical specs:
9mm Swan, 1.25" barrel
5/4 lenses/groups
72 degree FOV
12mm eye relief
Weight - 70g

15mm Swan, 1.25" barrel
5/4 lenses/groups
72 degree FOV
14mm eye relief
Weight - 90g

20mm Swan, 1.25" barrel
5/4 lenses/groups
72 degree FOV
17mm eye relief
Weight - 100g

25mm Swan, 2" barrel
5/3 lenses/groups
72 degree FOV
Eye relief 21mm
Weight - 330g

33mm Swan, 2" barrel
5/4 lenses/groups
72 degree FOV
25mm eye relief
Weight - 410g

40mm Swan, 2" barrel
5/3 lenses/groups
70 degree FOV
28mm eye relief
Weight - 570g

There are currently no specifications available for this product.

William Optics SWAN Eyepiece Questions & Answers

Please fill in the form below to ask a question.

Your Name
Your Email Address
Your Question

Average Rating (2 Reviews):  
Write a Review and share your opinions!

Rating (max 5):  
Good one for a Mak
Thursday, 5 May 2016  | 

I got the 15mm version to use with my Celestron C90 Maksutov, it gives 83x. Image quality is very good and distortion free (no barrel or pincushion that I notice). No chromatic aberration/astigmatism either, stars are sharp to the edge. The only complaint is that I don't believe the advertised 14mm eye relief; it's more like 10mm.
I've no idea how it would perform in a faster scope.

Rating (max 5):  
wide view eyepieces
Tuesday, 31 December 2013  | 

I use these eyepieces with my mack 180 pro 9 and15 are very good moon and planets people say that skywatcher mac carnt do deep sky using 25 to 40mm eyepieces it can

Customer Services Report
June 2018 / View Older
Positive Feedback read all 5,221 comments
Enquiries Responded to within 6 working hours
Orders Completed within 2 working days