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Diagonals & Accessories

Items 1 - 25 of 45
Apertura 2" Click Lock Carbon Dielectric Diagonal No adapter

Apertura 2" Twist Lock Carbon Dielectric Mirror Diagonal - D2CF

SKU: APT-D2CF
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
$129.95
 
Apertura 1.25" Carbon Dielectric Diagonal Full View

Apertura 1.25" Carbon Dielectric Mirror Diagonal - D1CF

SKU: APT-D1CF
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 1.25" Barrel
  • Diagonal Size - Telescope Side: 1.25" Barrel
  • Includes Eyepiece Adapter: No, 1.25" Eyepiece Adapter Sold Separately
  • Optics Type and/or Coatings: Dielectric Coatings
$79.95
 

Apertura 2" SCT Twist Lock Carbon Dielectric Mirror Diagonal - D2QCFSCT

SKU: APT-D2QCFSCT
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
$139.95
 
Apertura 2" Quartz Dielectric Diagonal

Apertura 2" Quartz Dielectric Diagonal - A-D2Q

SKU: APT-A-D2Q
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings , Quartz Optics
$129.95
 
Apertura 2" Dielectric Star Diagonal

Apertura 2" Dielectric Star Diagonal - A-D2

SKU: APT-A-D2
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
$109.95
 

Baader T2 BBHS Sitall Mirror Diagonal - MAX1S

SKU: BAD-MAX1S
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: T-2 Threads
  • Diagonal Size - Telescope Side: T-2 Threads
  • Optics Type and/or Coatings: BBHS Coatings , Sitall Optics
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$299.00
 
Baader Planetarium 2" ClickLock Mirror Diagonal

Baader MaxBright 2" Clicklock Mirror Diagonal - CLDIAG-2

SKU: BAD-CLDIAG-2
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: No, 1.25" Eyepiece Adapter Sold Separately
  • Optics Type and/or Coatings: Maxbright Coatings
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$309.00
 
Baader 2" BBHS Mirror Diagonal

Baader 2” BBHS Sitall Mirror Diagonal - MAX-2S

SKU: BAD-MAX-2S
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: No, 1.25" Eyepiece Adapter Sold Separately
  • Optics Type and/or Coatings: BBHS Coatings , Sitall Optics
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$499.00
 
William Optics 2" Dura Bright Dielectric SCT Diagonal

William Optics 2" Dura Bright Dielectric SCT Diagonal - D-DIG2D-C-DB-SCT

SKU: WYO-D-DIG2D-C-DB-SCT
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: SCT Threads
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: DuraBright Coatings
$158.00
 

Meade 2" Diagonal with SCT Adapter - 07680

SKU: MEA-07680
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel with SCT Adapter
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
$149.99
 

High Point SCT Dielectric Diagonal - 2" - HPS-D2SCT

SKU: HPS-D2SCT
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: SCT Threads
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
$114.95
 

High Point 2" SCT Quartz Dielectric Diagonal - D2QSCT

SKU: HPS-D2QSCT
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: SCT Threads
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings , Quartz Optics
$139.95
 

High Point 2" Quartz Dielectric Diagonal - HPS-D2Q

SKU: HPS-D2Q
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings , Quartz Optics
$129.95
 

High Point 2" Dielectric Mirror Diagonal - HPS-D2

SKU: HPS-D2
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
$109.95
 
High Point 1.25" Dielectric Mirror Diagonal

High Point 1.25" Dielectric Mirror Diagonal - HPS-D1

SKU: HPS-D1
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 1.25" Barrel
  • Diagonal Size - Telescope Side: 1.25" Barrel
  • Optics Type and/or Coatings: Dielectric Coatings
$69.95
 
Celestron 1.25" Dielectric Star Diagonal with Twist-Lock

Celestron 1.25" Dielectric Star Diagonal with Twist-Lock - 93571

SKU: CEL-93571
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 1.25" Barrel
  • Diagonal Size - Telescope Side: 1.25" Barrel
  • Optics Type and/or Coatings: Dielectric Coatings
$119.95 $114.95
 
Explore Scientific 2" Dielectric Diagonal

Explore Scientific 2" Dielectric Diagonal - DD02-00CF

SKU: EXS-DD02-00CF
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Dielectric Coatings
Free shipping Free shipping
$169.99
 
Celestron 2" Diagonal w/XLT Coatings for SCT

Celestron 2" Diagonal with XLT Coatings for Schmidt Cassegrain Telescopes - 93527

SKU: CEL-93527
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: SCT Threads
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: XLT Coatings
$159.95 $139.95
 
Tele Vue Richfield SCT Kit with 2" Everbrite Diagonal, SCT Adapter & 2" to 1.25" Adapter

Tele Vue 2" Everbrite Diagonal with SCT Adapter and 2" to 1.25" Adapter - SCP-8202

SKU: TLV-SCP-8202
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel with SCT Adapter
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Everbrite Coatings
Free shipping Free shipping
$371.00
 
William Optics 2" Dura Bright RotoLock Diagonal

William Optics 2" Durabright RotoLock Diagonal - D-DIG2D-ROTO-A2

SKU: WYO-D-DIG2D-ROTO-A2
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: No, 1.25" Eyepiece Adapter Sold Separately
  • Optics Type and/or Coatings: DuraBright Coatings
$198.00
 
Tele Vue 2" EverBrite Diagonal with Adapter Package

Tele Vue 2" Everbrite Diagonal with 2" to 1.25" Adapter - DDP-8004

SKU: TLV-DDP-8004
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Everbrite Coatings
Free shipping Free shipping
$320.00
 
TeleVue 2" Enhanced Mirror Diagonal Package

Tele Vue 2" Enhanced Aluminum Diagonal with 2"-to-1.25" Hi-Hat Adapter - DEP-8003

SKU: TLV-DEP-8003
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 2" Barrel
  • Diagonal Size - Telescope Side: 2" Barrel
  • Includes Eyepiece Adapter: Yes, 2" to 1.25"
  • Optics Type and/or Coatings: Enhanced Aluminum Coatings
Free shipping Free shipping
$261.00
 

Meade 918A Diagonal Mirror - 1.25" - 07202

SKU: MEA-07202
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 1.25" Barrel
  • Diagonal Size - Telescope Side: 1.25" Barrel
$29.99 $26.95
 

Tele Vue 1.25" 60 Degree Everbrite Mirror Diagonal - DPC-6012

SKU: TLV-DPC-6012
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 1.25" Barrel
  • Diagonal Size - Telescope Side: 1.25" Barrel
  • Optics Type and/or Coatings: Everbrite Coatings
$234.95
 

Tele Vue 1.25" 90 Degree Everbrite Mirror Star Diagonal - DPC-1250

SKU: TLV-DPC-1250
  • Diagonal Type: Mirror Diagonal
  • Diagonal Size - Eyepiece Side: 1.25" Barrel
  • Diagonal Size - Telescope Side: 1.25" Barrel
  • Optics Type and/or Coatings: Everbrite Coatings
$179.95
 

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.

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