FREE SHIPPING

On Hundreds of Products details ›

CALL US TOLL FREE 800-266-9590

Diagonals & Accessories

Back to Top
per page
  • Baader Planetarium 2
    Baader Planetarium Baader MaxBright 2" Clicklock Mirror Diagonal - CLDIAG-2
    $309.00
    Bread Checkout
     

    free shipping
  • Explore Scientific 2
    Explore Scientific Explore Scientific 2" Dielectric Diagonal - DD02-00CF
    $149.99
    Bread Checkout
     

    free shipping
  • High Point High Point 2" Dielectric Mirror Diagonal - HPS-D2
    $109.95
    Bread Checkout
     

    No free shipping.
  • High Point High Point 2" Quartz Dielectric Diagonal - HPS-D2Q
    $129.95
    Bread Checkout
     

    No free shipping.
  • Orion Orion 2" Dielectric Mirror Star Diagonal - 08727
    $129.99 $116.99
    Bread Checkout
     

    No free shipping.
  • Stellarvue Stellarvue 2" Correct Image 45° Erecting Prism - D1035
    $209.00
    Bread Checkout
     

    No free shipping.
  • William Optics 2
    William Optics William Optics 2" Dura Bright Dielectric Mirror Diagonal with Thermometer - D-DIG2D-C-DB
    $139.00
    Bread Checkout
     

    No free shipping.
  • Explore Scientific 3
    Explore Scientific Explore Scientific 3" Carbon Fiber Dielectric Diagonal - DD03-01CF
    $449.99
    Bread Checkout
     

    free shipping
  • Baader 2
    Baader Planetarium Baader Planetarium 2" Zeiss Prism Star Diagonal with BBHS Coatings & 2" ClickLock Eyepiece Clamp - PRISM-2Z
    $539.00
    Bread Checkout
     

    free shipping
  • Baader Planetarium Baader 2" 90-Degree Erecting Amici Prism Diagonal with 1.25" Adapter
    $299.00
    Bread Checkout
     

    free shipping
  • William Optics 2
    William Optics William Optics 2" Durabright RotoLock Diagonal - D-DIG2D-ROTO-A2
    $198.00
    Bread Checkout
     

    No free shipping.
  • Baader 2
    Baader Planetarium Baader 2” BBHS Sitall Mirror Diagonal - MAX-2S
    $499.00
    Bread Checkout
     

    free shipping
  • Takahashi 10th Wave 2
    Takahashi Takahashi 1/10th Wave 2" Diagonal with 1.25" Adapter - TKA00543
    $540.00
    Bread Checkout
     

    free shipping
  • Orion Twist-Tight Dielectric Mirror Diagonal - 2
    Orion Orion 2" Twist-Tight Dielectric Mirror Star Diagonal - 40902
    $149.99
    Bread Checkout
     

    free shipping
  • Baader Planetarium 2
    Baader Planetarium Baader 2" Astro Amici 90º Diagonal Prism with BBHS® Coating - AMICI-DX2
    $719.00
    Bread Checkout
     

    free shipping
  • Stellarvue 2
    Stellarvue Stellarvue 2" Dielectric Carbon Fiber Star Diagonal - D1028CF
    $189.00
    Bread Checkout
     

    No free shipping.
  • TeleVue 2
    Tele Vue Tele Vue 2" Enhanced Aluminum Diagonal with 2"-to-1.25" Hi-Hat Adapter - DEP-8003
    $261.00
    Bread Checkout
     

    free shipping
  • Tele Vue 2
    Tele Vue Tele Vue 2" Everbrite Diagonal with 2" to 1.25" Adapter - DDP-8004
    $320.00
    Bread Checkout
     

    free shipping
  • iOptron 2
    iOptron iOptron 2" Dielectric Star Diagonal - 6232
    $110.00
    Bread Checkout
     

    No free shipping.
  • Stellarvue Stellarvue 2" Quartz Dielectric Star Diagonal - D1040Q
    $249.00
    Bread Checkout
     

    free shipping
  • Explore Scientific 2
    Explore Scientific Explore Scientific 2" Dielectric Diagonal - DD02-00CF - Silver Grade Refurb
    $139.99 $104.99
    Bread Checkout
     

    free shipping
  • Apertura 2
    Apertura Apertura 2" Dielectric Star Diagonal - A-D2
    $109.95
    Bread Checkout
     

    No free shipping.
  • Apertura 2
    Apertura Apertura 2" Quartz Dielectric Diagonal - A-D2Q
    $129.95
    Bread Checkout
     

    No free shipping.
  • Celestron 2
    Celestron Celestron 2" Dielectric Star Diagonal with Twist-Lock - 93573
    $189.95 $184.95
    Bread Checkout
     

    free shipping
Back to Top
per page

A star diagonal is a useful astronomy accessory because it allows viewers to look through their telescope perpendicular to the direction the telescope points or at a 45° angle. This makes diagonals handy for terrestrial observations as well. The people at High Point Scientific understand that the comfort and convenience of using a star diagonal is important to you, that is why we offer many different types of telescope diagonals for you to choose from. You will find the latest brands offering a variety of diagonals, including mirror, dielectric, and prism diagonals.


As the name suggests, mirror diagonals use a mirror to turn the telescope’s image at a 90° or 45° angle. This creates an image that is correctly oriented vertically but reversed horizontally. The mirror is typically made of silver or aluminum, both of which scratch easily. You will need to careful when cleaning and using your mirror diagonal. However, mirror diagonals are often very affordable which makes them a favorite among amateur astronomers.


Many astronomers prefer mirror diagonals but wish they were more durable. That’s why High Point Scientific also offers dielectric diagonals. Dielectric diagonals are mirror diagonals but include enhanced dielectric coatings for greater durability and reflectivity. These coatings make dielectric diagonals hard and sturdy so it is much more difficult to scratch or mar mirror surfaces.


Prism diagonals are often considered the most innovative design for a diagonal. They use a glass prism that often produces higher reflectivity than mirror or dielectric diagonals. This means that prism diagonals suffer minimal light loss to give you high contrast celestial views. Be sure to look for Amici prism diagonals on the High Point Scientific website, as these produce an upright image with a correct left-right view for low-powered eyepieces.

High Point Scientific is rated 4.9/5 based on 1347 reviews

Please wait...