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William Optics 1.25" UWAN Series Eyepiece - 4mm

3.3 (3 Reviews) Read Reviews Write Review
Brand William Optics
Part Number E-UWA04
Availability available

Product Info

Manufacturer Description

Beautiful Ultra Wide Angle (UWA) Eyepiece, for beautiful observation sessions with your telescope. This 7-element UWAN eyepiece is ideal for rich-field observations at medium-high power.Extremely good price for its quality: look around and compare! Ideal for fast focal ratio telescopes (Dobsonian, etc.)

Super Wide FOV
Outstanding ultra-wide field of view: 82 deg. F.O.V.
Fully MultiCoated lenses for excellent light transmittance.
Reduced chromatic aberration.
Improved contrast compared to similar EPs.

Great Contrast
Internally fully blackened (lenses edges and internal spacers)
No flaring or ghosting on high-contrast objects.
Parfocal

Light and Easy
Innovative twist-up rubber eyecup.
Long eye-relief: 12mm.
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.

Reviews

3.3 (Based on 3 Reviews) 67% of reviewers recommended this product.
Rating Distribution
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    1. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by telescope tom of Tucson.
      1410048000
      Sep 6, 2014

      5.0 Really good

      Pros:

      Quality Lenses

      Cons:

      Comments:

      Just a little bit better than the Radian 4mm it replaced, wider field was great for Mars with my non tracking dob.

      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 MrPeddlePaddle of Vancouver, Canada.
      1391904000
      Feb 8, 2014

      1.0 A wild light show

      Pros:

      Lightweight

      Cons:

      Comments:

      There are few 4mm, wide-field eyepieces, so I was looking forward to this 82 deg ocular for use in my 80mm f/7 Stellarvue ED refractor. In that scope it yields 141x, which I thought would make it my "workhorse" lens for that scope.

      Unfortunately, attempting to use the lens on a bright object like Jupiter let to such bright and uncontrolled flaring/ reflections that it only lasted a few minutes in the scope.

      I will try it again for some open-cluster use, but it has been a very disapointing purchase.

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

      This review was provided courtesy of AgenaAstro.com

    3. Guest

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by vic of San Mateo, CA.
      1324857600
      Dec 25, 2011

      4.0 Good selection

      Pros:

      Quality Lenses,Strong Construction

      Cons:

      Comments:

      Love this lens, gives me the highest power for my 90mm William scope...

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

      This review was provided courtesy of AgenaAstro.com

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      Specifications

      Apparent Field of View 82°
      Barrel Size 1.25" (31.7mm)
      Bolt Case Included Yes - Free Agena Eyepiece Container
      Bolt Case Size Agena 52x80mm
      Coatings Fully Multi-Coated
      End Caps 2
      Eye Relief by Design 12mm
      Field Stop Diameter 6mm
      Filter Threads Standard 1.25" Filter Thread (M28.5 x 0.6)
      Focal Length 4mm
      Lens Elements 7
      Lens Groups 4
      Parfocal Yes
      Rubber Eye Guard Yes (Twist-Up Eyecup)
      Blackened Lens Edges Yes
      Manufacturer William Optics
      Eyepiece Focal Length 5mm and Under
      Eyepiece Field of View Over 80 degrees
      Eyepiece Series William Optics UWAN
      Barrel Type Tapered barrel
      Eyepiece Weight 7.05oz (200g)