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William Optics 1.25" 45-deg Erecting Prism Diagonal

4.9 (11 Reviews) Read Reviews Write Review
Brand William Optics
Part Number D-EP125
Availability available

Product Info

Manufacturer Description

William Optics new 45° EP will work with any 1.25" eyepieces and most scopes with 1.25" eyepiece holders (Please note that diagonals cannot be used with Newtonian or Dobsonian reflector telescopes). It will turn upside down images right side-up and give correct left-to-right image. This high-quality, low-cost erecting prism will set the standard in erecting prisms!

Large Prism
• Large, high-quality BAK4 erecting prism with anti-reflection coating allows for good contrasted and bright images.
• Brass compression ring.

Great Price
• 1.25" eyepiece holder comes with anti-marring brass compression ring.
• Extremely competitive price/quality ratio.

Innovative Shape
• Entirely aluminum, black anodized eyepiece holder.
• Large, chromed thumbscrews.

Advanced Craftsmanship
• Internally matte blackened and threaded for no internal stray light reflection.

Features:
Prism: High quality BAK4 with anti-reflection coating
Materials: Entirely machined aluminum
Angle: 45 degree
Prism clear aperture: 25mm; 1.25" with brass compression rings
Weight: 6 oz

Reviews

4.9 (Based on 11 Reviews) 100% of reviewers recommended this product.
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    1. Guest

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      Review by John B.
      1513246483
      Dec 14, 2017

      5.0 William Erecting Prism

      Pros:

      Cons:

      Comments:

      A really great purchase. My refractor telescope is now great for terrestrial viewing

      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 timothy c.
      1501352886
      Jul 29, 2017

      5.0 williams optics 1.25 45 degree erecting prism

      Pros:

      Cons:

      Comments:

      solidly built unit excellent optics has compression ring too securely holds binoviewers i am satisfied.

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

      This review was provided courtesy of AgenaAstro.com

    3. Guest

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      Review by John C.
      1497883232
      Jun 19, 2017

      5.0 A delight to look through and to look at. William Optics at its best.

      Pros:

      Cons:

      Comments:

      A gorgeous piece of workmanship both physically and optically. It has just enough heft without being too heavy. Optically it is outstanding - so far ahead of the plastic one that came with the scope words can't describe it. I own numerous W.O. telescopes, diagonals and eyepieces. All are superb. This correct-view diagonal did not disappoint me. I'm sure it will delight you, too.

      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 Matt of Melbourne, Victoria Australia.
      1475193600
      Sep 29, 2016

      5.0 Fantastic results and flexibility.

      Pros:

      Easy to Use,Compact,Quality Lenses,Lightweight,Accurate,Strong Construction

      Cons:

      Comments:

      Exceptional value for money. Far superior over the one that's supplied with my celestron nexstar. Excellent light transmission and a clear image. High quality, well made piece that delivers. It is great having a 90 deg and 45 deg piece in your kit bag. Highly recommended product. Thank you to Agena for your stellar service and top items.

      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 Tom of Ohio.
      1396051200
      Mar 28, 2014

      5.0 Quality optics for terrestrial viewing

      Pros:

      Lightweight,Quality Lenses,Easy to Use,Strong Construction

      Cons:

      Comments:

      Works great with my C6 for use as a spotting scope, bird watching and terrestrial viewing. Built solidly and excellent fit and finish.

      Very nice item, IMO.

      As always, service was great at Agena Astro.

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

      This review was provided courtesy of AgenaAstro.com

    6. rmscott59

      rmscott59 New Member

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      Review by RMS of SF, CA.
      1354233600
      Nov 29, 2012

      5.0 Well worth the money!!!

      Pros:

      Quality Lenses,Strong Construction,Lightweight

      Cons:

      Comments:

      A definite improvement in brightness, contrast and clarity over "supplied" diagonals. Don't expect to see staggering differences, but definite, subtle improvements to be sure. This is a quality product that you can purchase with confidence that you will be satisfied. I know I am not supposed to mention the OUTSTANDING customer service that is automatic with any AGENA purchase.....so I won't go into that!!

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

      This review was provided courtesy of AgenaAstro.com

    7. Guest

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      Review by Old Starman of Houston, Texas.
      1335744000
      Apr 29, 2012

      4.0 Affordable Quality

      Pros:

      Accurate,Strong Construction,Quality Lenses

      Cons:

      Comments:

      Well made. No-mar eyepiece securement

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

      This review was provided courtesy of AgenaAstro.com

    8. Guest

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      Review by Andy of Calgary, AB.
      1320364800
      Nov 3, 2011

      5.0 Well manufactured piece of kit

      Pros:

      Quality Lenses,Strong Construction

      Cons:

      Comments:

      A very good quality diagonal. Does not feel cheap, like others out there. You do get what you pay for. I use this for mainly daytime use but will use it when observing the moon on occasion. If in need of an erecting diagonal, do not be leery to spend the extra over a lesser quality one.

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

      This review was provided courtesy of AgenaAstro.com

    9. Guest

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      Review by chris of Ile-de-france, France.
      1319932800
      Oct 29, 2011

      5.0 I would buy this product again

      Pros:

      Quality Lenses,Easy to Use,Strong Construction

      Cons:

      Comments:

      Beautiful construction, good optical quality. The images are contrasted.

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

      This review was provided courtesy of AgenaAstro.com

    10. Jim Thompson

      Jim Thompson New Member

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      1258838400
      Nov 21, 2009

      5.0 William Optics 1.25" 45deg Erecting Prism

      Pros:

      Handsome styling; good optical performance; good price

      Cons:

      Not as easy to find

      Comments:

      A fine quality prism. The care taken in the details is evident when you hold it in your hand. Nice smooth finish, large knurled thumbscrew, threading and flat black paint on the inside to cut reflections. This prism has a very slick design, and great optical performance. It uses a better performing coated BAK-4 prism. All this for a reasonable price.

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

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      Review by Doug in TN of Oak Ridge, TN.
      1235001600
      Feb 18, 2009

      5.0 A Fine Erecting Diagonal

      Pros:

      Superior image quality,Good quality large prism,Good looking exterior

      Cons:

      Comments:

      I wanted a 45 degree erecting diagonal to use with my 6" f5 achro. I have a nice 90 degree diagonal for stargazing, and the erecting diagonal was to be for casual terrestrial use. First I tried a model from one of the major mass astro sellers. It did what it was meant to do, but the construction was mostly plastic, and I wasn't particularly impressed by the quality of the images, which were somewhat dim and muddy looking, so I decided to try the 45 degree erector from a major maker of high end scopes and eyepieces and was surprised to find it to be very similar in construction to the first one. The clear aperture of both prisms was small, and I could see the edges of the prism in the second one by looking thru each end of the diagonal. No surprise that image quality in it was not even as good as in the first. It appeared that the concept of a good quality 45 degree erecting prism diagonal was not taken seriously by the big players in the astro equipment field.Or so It seemed until I came across the William Optics 1.25 Inch 45 Erecting Prism Diagonal on the Agena Astro Products website. Externally it is very different in appearance from the typical erecting diagonal. Whereas the common erecting diagonal prism is angular and the prism housing is shaped like a pyramid, the WO diagonal is more esthetically pleasing in that it is consists mainly of curved shapes. The prism housing is round, and the eyepiece adapter tube exterior sides are concave. The unit is a handsome black and chrome. It's made entirely of aluminum. Best of all, though, is the prism. It's large, with 25mm clear aperture, made of BAK4 glass and with anti-relection coating. As soon as I had inserted the WO diagonal with a generic 37X Plossl ep in my scope I could see that this erecting diagonal gave images that were far and away better than the other diagonals. Bright, sharp, and contrasty up to about 80X, I had found the erecting diagonal I was beginning to think didn't exist. This was my first experience with William Optics products. Seeing the handsome white box with the red swan logo, and the manner in which the diagonal was packed in a solid block of foam did not fail to make an initial favorable impression. This is what one expects with high-end expensive astro accessories (but often doesn't get). And here's the kicker-I paid only [$]for this item. It's a steal at that price.Agena Astro Products aims for customer satisfaction. Obviously I am very pleased with the WO diagonal[...]

      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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