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William Optics 2" 45-deg Erecting Prism Diagonal # D-EP2

4.5 (6 Reviews) Read Reviews Write Review
Brand William Optics
Part Number D-EP2
Availability available

Product Info

Manufacturer Description

William Optics' 2" 45-deg erecting prism will scream to be used with that nice premium refractor of yours! Perfect for daytime observations. No further description is needed: just check it out!

Precision Prism
- Image erecting BAK4 prism with anti-reflection coating.
- High accuracy and high light reflection prism.
- Brass compression ring.

Superior Craftsmanship
- Internally matte blackened and threaded for no internal stray light reflection.
- Threaded for 2" filters.

Ready to Go
- 1.25" adapter with brass compression ring included.
- Large, chromed thumbscrews.

Beautiful Finish
- Entirely aluminum, black anodized.
- Smooth finish.

Features:
- Prism: High quality BAK4 with anti-reflection coating
- Materials: Entirely machined aluminum
- Angle: 45 degree
- Prism clear aperture: 31mm
- 2"-1.25" adapter with brass compression rings
- Weight: 400g

Note that this diagonal is not recommended for astronomical use as the prism edges will create spikes in star images.

Reviews

4.5 (Based on 6 Reviews) 100% of reviewers recommended this product.
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    1. Guest

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      Review by John M.
      1482594006
      Dec 24, 2016

      5.0 Does exactly what I want it to!

      Pros:

      Cons:

      Comments:

      I needed a terrestrial viewer for my Televue 102/Gibraltar combo, this fit the bill perfectly. Very sharp terrestrial viewing with the 35 Panoptic and, especially, the 12MM Nagler eyepieces. No problem with diffraction patterns on terrestrial viewing, but it won’t work for astronomical viewing so well. But I have the Televue Everclear for that! Great quality diagnonal!

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

      This review was provided courtesy of AgenaAstro.com

    2. Guest

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      Review by Bino Gwen of Upstate NY.
      1335744000
      Apr 29, 2012

      5.0 * First Class * Well Made * AAAA++ Item

      Pros:

      Easy to Use,Strong Construction,Quality Lenses,Nicely Built

      Cons:

      None

      Comments:

      This is the nicest 45-deg erecting prism I have ever used. It should cost more, a real steal at the current price.

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

      This review was provided courtesy of AgenaAstro.com

    3. roaesch

      roaesch New Member

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      Review by Roaesch of Moscow, ID.
      1330128000
      Feb 24, 2012

      4.0 Stunning terrestrial viewing.

      Pros:

      Strong Construction,Easy to Use,Good Looking

      Cons:

      Poor night views

      Comments:

      This erecting prism will allow you to use your 2" 100 degree eyepieces for stunning terrestrial viewing! It converts an astronomical telescope into a great terrestrial viewer. It doesn't do well on the night sky though, as the prism delivers a horizontal diffraction spike that is annoying. This is just a fact that comes with an amici prism.

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

      This review was provided courtesy of AgenaAstro.com

    4. Guest

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      Review by Star Gazer of Bandera, Texas.
      1324080000
      Dec 16, 2011

      3.0 Good for nature study but not astronomy

      Pros:

      Lightweight,Compact,Easy to Use

      Cons:

      Mediocre optical quality,Significant path length

      Comments:

      I would only recommend this product for daytime nature study. The 45 degree angle is great for nearly horizontal viewing, and having a correct left-right image is an advantage compared to a 90 degree diagonal. The only issue here is the extra 125 mm of back focus path length required. With my Explore Scientific 80 mm scope I cannot reach focus with some eyepieces (including the Baader 8-24 mm zoom). I would not recommend this product for general nighttime viewing because the image quality is degraded such that significant aberrations are very noticeable in star images.

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

      This review was provided courtesy of AgenaAstro.com

    5. Guest

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      Review by Michael of Wellington, Florida.
      1303084800
      Apr 17, 2011

      5.0 William Optics 2" 45-deg Erecting Prism

      Pros:

      Strong Construction,Quality Lenses,Accurate

      Cons:

      Comments:

      Great product(s) and enjoy very much doing business here. Thanks.

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

      This review was provided courtesy of AgenaAstro.com

    6. Guest

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      Review by Ed of Boise, ID.
      1291593600
      Dec 5, 2010

      5.0 William Optics Diagonal

      Pros:

      Great finish,Strong Construction

      Cons:

      None

      Comments:

      I needed a 2" erecting diagonal for my 8" Meade LX-200 SCT type telescope for terrestrial viewing so that the image is not inverted left-to-right. But Meade does not make an erecting type diagonal for 2" eyepieces (only for 1.25" eyepieces). However, the William Optics 2" 45-deg Erecting Prism Diagonal worked great. Since it is a diagonal made for refractor type scope, it needed the Williams Optics SCT Thread Adapter to attach to the back of my SCT telescope. You simply unscrew the 2" noise piece from the diagonal and replace it with the adaptor. This, effectively, converts the diagonal from a refractor type into an SCT type (i.e. which will screw onto the back of my SCT type telescope).

      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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