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

GSO 1.25" 45-deg Erect Image Amici Prism Diagonal # PD45

4.1 (7 Reviews) Read Reviews Write Review
Brand GSO
Part Number PD45
Availability available

Product Info

Manufacturer Description

GSO's 1.25" 45-degree diagonal features an image erecting Amici glass prism that allows you to look into a telescope at a 45 degree angle. It produces an image that is oriented properly, which means that the image is upright and correct from left to right (i.e., a correct, non-inverted, non-reversed image).

This is a great diagonal for daytime terrestrial use with small telescopes or spotting scopes. It can also be used for nighttime astronomy applications, especially when you would like to match the orientation of the star field with "correct" star maps and charts.

The clear aperture is 19.5mm. The prism housing is made of high grade ABS plastic and the end barrels are made from precision machined aluminum. The 1.25" nosepiece is threaded to accept standard 1.25" astronomy filters. The diagonal comes with 2 end caps and weighs 3.8oz. Made in Taiwan.

Please Note: This diagonal can only be used with refractor telescopes and some catadioptric telescopes like Schmidt-Cassegrain, Maksutov-Cassegrain, etc. It not meant for use with Newtonian / Dobsonian reflector telescopes or other variants of Newtonian telescopes.

Reviews

4.1 (Based on 7 Reviews) 86% 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 David A.
      1495300219
      May 20, 2017

      4.0 Inexpensive, good for daytime use.

      Pros:

      Cons:

      Comments:

      Wanted an erect image diagonal for a short tube 80 refractor used for bird watching during the day. Works well for that.

      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 sarchosucus imperator of Bryan OH.
      1424563200
      Feb 21, 2015

      3.0 Not the Same Quality Level

      Pros:

      Easy to Use,Lightweight,Strong Construction

      Cons:

      Comments:

      This item does not display the same level of quality I expect from GSO, given other products made by them that I own. The body of the diagonal is made of an injection-molded plastic piece, which is less stable than a machined aluminum alternative. I would have paid more for it.

      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 PH of Passo de Torres, SC, Brazil.
      1341100800
      Jun 30, 2012

      5.0 Very good quality. Fair price.

      Pros:

      Quality Lenses,Accurate,Easy to Use,Lightweight

      Cons:

      Comments:

      The only remark: The GSO brand isn't marked on the diagonal. Something that was said to be a normal practice among several others manufacturers.
      Anyway, the quality is good enough for terrestrial use.
      I didn't use it for astronomy.

      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 fahema2012 of Zaragoza, Spain.
      1320537600
      Nov 5, 2011

      5.0 IS SIMPLY GSO goods items for good price

      Pros:

      Quality,Compact,Weight,Lightweight,Quality Lenses,Easy to Use,Strong Construction,Price

      Cons:

      Comments:

      I think is better you can buy for this price. is simple Is good and clear and light weight, and resistant

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

      This review was provided courtesy of AgenaAstro.com

    5. dmbryan

      dmbryan New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by DB of Birmingham, AL.
      1249603200
      Aug 6, 2009

      4.0 Nice solid diagonal

      Pros:

      Accurate,Strong Construction,Quality Lenses,Compact

      Cons:

      Comments:

      This is a quality piece of equipment. It works quite well on my 80mm refractor.

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

      This review was provided courtesy of AgenaAstro.com

    6. dmbryan

      dmbryan New Member

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      1246597620
      Jul 2, 2009

      4.0 A good buy

      Pros:

      Solid construction. ease of use.

      Cons:

      none

      Comments:

      I purchased this product for use with my 80mm refractor. My son has a hard time seeing through a 90 degree diagonal due to his height. This is a solid product. It is much better than the diagonal that came with my scope. The images are very clear. I am very pleased with this product.

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

      Skill Level
      Unknown
      Time with Product
      Unknown
      User Notes:
      Review by Baja observer of Tijuana, Baja California.
      1235001600
      Feb 18, 2009

      4.0 Correct image

      Pros:

      Cons:

      Comments:

      This is the diagonal I use the most, I have a window on my office that looks to the ocean and I like this diagonal on my 80mm refractor (that lives there) just to look ships on the horizon, also the greenflash is stuning.
      I love to see things on the ocean upright not sideways or upsidedown like with my 1.25 dielectric diagonal (for night use).
      I do not justify spending a lot of money on a diagonal with more reflectivity if Im going to use it on daylight.
      I recommend this diagonal.

      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

      Manufacturer GSO