Dismiss Notice
New Cookie Policy
On May 24, 2018, we published revised versions of our Terms and Rules and Cookie Policy. Your use of AstronomyConnect.com’s services is subject to these revised terms.

More Views

William Optics 2" Swan Series Eyepiece - 25mm

4.5 (6 Reviews) Read Reviews Write Review
Brand William Optics
Part Number E-SWA25
Availability available

Product Info

Manufacturer Description

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 25mm SWAN EP's panoramic views at 72 deg. FOV will leave you speechless!  A premium eyepiece at a fraction of the cost its worth!

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.
Very Long eye-relief: 21mm.
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 2" filters.

Reviews

4.5 (Based on 6 Reviews) 100% of reviewers recommended this product.
Rating Distribution
Sort by
  • Date
  • Rating
  • Useful
    1. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by mike c.
      1530332874
      Jun 29, 2018

      5.0 excellent product and FAST shipping!

      Pros:

      Cons:

      Comments:

      excellent product and FAST shipping!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    2. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Ray in Corrales NM of Corrales, NM.
      1457740800
      Mar 11, 2016

      4.0 Perfect complement to 40mm eyepiece

      Pros:

      Strong Construction,Crisp,Wide Angle,Quality Lenses

      Cons:

      Comments:

      I bought the 25mm a few months after my purchase of the Swan 40mm, 2 inch eyepiece. These two eyepieces are my two favorites. I use them while observing deep space objects.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    3. Nick Salt

      Nick Salt New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Nick of Ontario, Canada.
      1422403200
      Jan 27, 2015

      4.0 No problems

      Pros:

      Cons:

      Comments:

      I use this on my 10" f/4.7 dobsonian. I find you don't notice the coma unless you are specifically looking for it. Excellent views and one of my most useful eyepieces in my collection. Would definitely recommend to the amateur astronomer on a budget. I'm sure there are better options but for the price you cannot beat it.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    4. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by aldebaran of Pozuelo del Rey (Madrid).
      1352160000
      Nov 5, 2012

      4.0 GOOD EYEPIECES

      Pros:

      Strong Construction,Compact,Quality Lenses

      Cons:

      Coma

      Comments:

      Excellent eyepiece focal above F6

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    5. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by chris of Ile-de-france, France.
      1319932800
      Oct 29, 2011

      5.0 I would buy this product again

      Pros:

      Quality Lenses,Strong Construction

      Cons:

      Comments:

      Beautiful construction, completed for my Meade LX90, excellent aberation correction.

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    6. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Ed of NorthEast.
      1227571200
      Nov 24, 2008

      5.0 SUPER VALUE HIGH PREFORMANCE EYEPIECE

      Pros:

      Comfortable Eyepiece,Quality Lenses,Strong Construction

      Cons:

      Comments:

      Edge to edge sharp images!

      Bottom Line: Would you recommend this item? Yes
      Was this review helpful? Yes / No

      This review was provided courtesy of AgenaAstro.com

    Sort by
    • Date
    • Rating
    • Useful

      Specifications

      Apparent Field of View 72°
      Barrel Size 2" (50.8mm)
      Bolt Case Included Yes - Free Agena Eyepiece Container
      Bolt Case Size Agena 65x80mm
      Coatings Fully Multi-Coated
      End Caps 2
      Eye Relief by Design 21mm
      Filter Threads Standard 2" Filter Thread (M48 x 0.75)
      Focal Length 25mm
      Lens Elements 5
      Lens Groups 3
      Parfocal Yes
      Blackened Lens Edges Yes
      Manufacturer William Optics
      Eyepiece Focal Length 20.1mm - 30mm
      Eyepiece Field of View 71 - 80 degrees
      Eyepiece Series William Optics SWAN
      Barrel Type Tapered barrel
      Eyepiece Weight 11.64oz (330g)