10 Best Telescope Diagonals for January 2021

Recommendations are independently chosen by MOOZ’s editors. Purchases you make through our links may earn us a commission.

1
Celestron 2-Inch XLT Diagonal Mirror (for SCT Telescope)
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Celestron 2-Inch XLT Diagonal Mirror (for SCT Telescope)

by Celestron
What We like

Includes a 2 to 1.25 adapter and aluminum carry case

more infoarrow_drop_down

Product Features

  • 1/10th wave mirror is tested with an interferometer to ensure quality
  • 2 SCT mirror diagonal with high performance XLT coatings
  • Housing is precision machined to achieve and hold good optical alignment.

Housing is precision machined to achieve and hold good optical alignment. 1/10th wave mirror is tested with an interferometer to ensure quality 2 sct mirror diagonal with high performance xlt coatings

2
Astromania 2
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Astromania 2" 45-Degree Erecting Prism Diagonal for Telescope

by Astromania
What We like

1.25" adapter with brass compression ring included.

more infoarrow_drop_down

Product Features

  • Image erecting BAK4 prism with anti-reflection coating.
  • High accuracy and high light reflection prism.
  • Internally matte blackened and threaded for no internal stray light reflection.

High accuracy and high light reflection prism. Image erecting bak4 prism with anti-reflection coating. Internally matte blackened and threaded for no internal stray light reflection.

3
SVBONY 2 inches 90 Deg Dielectric Mirror Diagonal for Astronomical Telescope with 1.25 inches Adapter
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

SVBONY 2 inches 90 Deg Dielectric Mirror Diagonal for Astronomical Telescope with 1.25 inches Adapter

by SVBONY
What We like

Excellent Quality Dielectric Diagonal; Mirror Star Diagonal - 99% ReflectivityProvides a Comfortable 90 Degree View from your Refractor; Fits Standard 2" (50.8 mm) Diameter Focus Tubes; Use Both 2" (50.8 mm) and 1.25" (31.75 mm) Eyepieces

more infoarrow_drop_down

Product Features

  • New 2" 90 deg 99% Dielectric Mirror Diagonal for Telescope With 1.25" adapter; full metal;has a 1/10th wave flat optical glass surface;solid aluminum housing;threaded to accept standard 2" filters;The 2" eyepiece holder uses a non-marring brass compression ring to secure your valuable eyepieces. The 1.25" adapter also has a non-marring brass compression ring
  • Dielectric diagonal is especially important;A standard aluminized diagonal has about 92% reflectance;And this decreases with time as the aluminum mirror surface ages
  • For the vast majority of the visible spectrum;the reflectance does not vary more than about 0.1% below 100%;And the dielectric surface does not age like aluminum;This combination leads to the equivalent of a little more light grasp compared to standard diagonals
  • Both sizes of eyepieces may be used and are protected from dings and scratches that would result from a standard set-screw. This 2" diagonal works with any Refractor that accepts a 2" star diagonals. It can also be used with Schmidt-Cassegrain or Maksutov-Cassegrain with an optional 2 inch visual back (See below)

For the vast majority of the visible spectrum;the reflectance does not vary more than about 0.1% below 100%;and the dielectric surface does not age like aluminum;this combination leads to the equivalent of a little more light grasp compared to standard diagonals Both sizes of eyepieces may be used and are protected from dings and scratches that would result from a standard set-screw. this 2" diagonal works with any refractor that accepts a 2" star diagonals. it can also be used with schmidt-cassegrain or maksutov-cassegrain with an optional 2 inch visual back (see below) New 2" 90 deg 99% dielectric mirror diagonal for telescope with 1.25" adapter; full metal;has a 1/10th wave flat optical glass surface;solid aluminum housing;threaded to accept standard 2" filters;the 2" eyepiece holder uses a non-marring brass compression ring to secure your valuable eyepieces. the 1.25" adapter also has a non-marring brass compression ring Dielectric diagonal is especially important;a standard aluminized diagonal has about 92% reflectance;and this decreases with time as the aluminum mirror surface ages

4
Dielectric Mirror, 1.25 Inch 90-Degree Dielectric Mirror Diagonal for Telescope
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Serounder Dielectric Mirror

1.25 Inch 90-Degree Dielectric Mirror Diagonal for Telescope

by Serounder
What We like

Not recommended for use in reflective telescopes.

more infoarrow_drop_down

Product Features

  • Interface with 1.25 inch thread can be connected with 1.25in filter.
  • Constructed with aluminum alloy housing and stainless steel cover plate, available for long lifespan.
  • All-surface multilayer coated.
  • Used for 1.25 inch focus seat and 1.25inch eyepiece.

Constructed with aluminum alloy housing and stainless steel cover plate, available for long lifespan. All-surface multilayer coated. Used for 1.25 inch focus seat and 1.25inch eyepiece. Interface with 1.25 inch thread can be connected with 1.25in filter.

5
Gosky 0.965Inch Telescope Accessory Kit for 0.965 Telescope - with Four Eyepieces, one Diagonal, a 3X Barlow Lens
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Gosky 0.965Inch Telescope Accessory Kit for 0.965 Telescope

with Four Eyepieces, one Diagonal, a 3X Barlow Lens

by Gosky
What We like

A 90 degree diagonal.

more infoarrow_drop_down

Product Features

  • 4mm/6mm/12.5mm/ 20mm eyepieces for different power in any telescope.
  • It contains 4mm/6mm/12.5mm/ 20mm eyepiece, a 2x berlow lens and 90 degree diagonal.
  • Barlow lens A visual Barlow, doubles the magnification of any inserted 0.965 inch eyepiece.
  • This six-piece 0.965inch astronomy accessory kit let you get the most out and enhances the performance of your telescope.

It contains 4mm/6mm/12.5mm/ 20mm eyepiece, a 2x berlow lens and 90 degree diagonal. 4mm/6mm/12.5mm/ 20mm eyepieces for different power in any telescope. This six-piece 0.965inch astronomy accessory kit let you get the most out and enhances the performance of your telescope. Barlow lens a visual barlow, doubles the magnification of any inserted 0.965 inch eyepiece.

6
Orion 8850 2-Inch Refractor Telescope Mirror Diagonal
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Orion 8850 2-Inch Refractor Telescope Mirror Diagonal

by Orion
What We like

Mirror diagonal with a 90 degrees design features polished optics to yield maximum performance of big 2" telescope eyepieces

more infoarrow_drop_down

Product Features

  • 2" diagonal for use with refractor telescopes
  • Fits 2" focusers on refractor telescopes
  • A convenient accessory for switching between large 2" and 1.25" eyepieces when viewing with a refractor telescope
  • Accepts 2" eyepieces and includes 1.25" eyepiece adapter for use with smaller 1.25" eyepieces and accessories

A convenient accessory for switching between large 2" and 1.25" eyepieces when viewing with a refractor telescope Fits 2" focusers on refractor telescopes 2" diagonal for use with refractor telescopes Accepts 2" eyepieces and includes 1.25" eyepiece adapter for use with smaller 1.25" eyepieces and accessories

7
SVBONY SV138 Diagonal Mirror 1.25 inch 45 degree Correct Image Prism Diagonal Mirror Fully Metal for Refractor Astronomy Telescope with Dust Cover
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

SVBONY SV138 Diagonal Mirror 1.25 inch 45 degree Correct Image Prism Diagonal Mirror Fully Metal for Refractor Astronomy Telescope with Dust Cover

by SVBONY
What We like

Unique brass ring design;Provides a uniform pressure-receiving area when holding the eyepiece; not only is it fixed more firmly;it does not damage your expensive eyepieces

more infoarrow_drop_down

Product Features

  • Correct upside down and left-right reversed image easily;Even if you want to observe wildlife or other scenery during the day;SV138 diagonal mirror can also easily provide you with the right image
  • The SV138 45-deg correct-image diagonal requires 5/8" more focus travel than typical diagonals;Not recommended for use in Newtonian reflector or Dobsonian reflector telescopes
  • Fully multi-coated prisms for superior image fidelity and maximum light throughput;Effectively reduce the light loss of your light during transmission to improve the brightness and color saturation of the image
  • High quality CNC manufacturing;aluminum alloy housing and stainless steel cover;Extend SV138 diagonal mirror life and make it more durable without worrying about damage during use

The sv138 45-deg correct-image diagonal requires 5/8" more focus travel than typical diagonals;not recommended for use in newtonian reflector or dobsonian reflector telescopes Fully multi-coated prisms for superior image fidelity and maximum light throughput;effectively reduce the light loss of your light during transmission to improve the brightness and color saturation of the image High quality cnc manufacturing;aluminum alloy housing and stainless steel cover;extend sv138 diagonal mirror life and make it more durable without worrying about damage during use Correct upside down and left-right reversed image easily;even if you want to observe wildlife or other scenery during the day;sv138 diagonal mirror can also easily provide you with the right image

8
Orion 8787 1.25-Inch Correct-Image Star Telescope Diagonal
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Orion 8787 1.25-Inch Correct-Image Star Telescope Diagonal

by Orion
What We like

Provides a view through your telescope that matches normal daytime orientation for added comfort and ease of use

more infoarrow_drop_down

Product Features

  • For terrestrial or astronomical use, this1.25" 90 degrees diagonal produces a right-side-up, no reversed image
  • Requires no extra focus travel
  • Fully coated prisms for superior image fidelity
  • Not intended for use with reflector telescopes

Not intended for use with reflector telescopes Requires no extra focus travel For terrestrial or astronomical use, this1.25" 90 degrees diagonal produces a right-side-up, no reversed image Fully coated prisms for superior image fidelity

9
Orion 8763 1.25-Inch Prism Star Telescope Diagonal
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Orion 8763 1.25-Inch Prism Star Telescope Diagonal

by Orion
What We like

Makes it easier to navigate the nigth skies with a telescope

more infoarrow_drop_down

Product Features

  • Fully coated prisms for superior image fidelity
  • Accepts 1.25" telescope eyepieces
  • For astronomical use, this diagonal produces an image that's right-side-up, reversed left to right
  • Useful fro refractor and Cassegrain telescopes - not recommended for reflectors

For astronomical use, this diagonal produces an image that's right-side-up, reversed left to right Accepts 1.25" telescope eyepieces Fully coated prisms for superior image fidelity Useful fro refractor and cassegrain telescopes - not recommended for reflectors

10
Orion 7216 1.25-Inch 45-degree Correct Image Prism Telescope Diagonal
design_servicesDESIGN
miscellaneous_servicesUTILITY
handymanUSABILITY

Orion 7216 1.25-Inch 45-degree Correct Image Prism Telescope Diagonal

by Orion
What We like

Requires 5/8" more focus travel than typical star diagonals

more infoarrow_drop_down

Product Features

  • For terrestrial or astronomical use, this diagonal produces a right-side-up, non-reversed image with correct daytime orientation
  • Accepts 1.25" eyepieces, fits in 1.25" focusers
  • Fully coated prisms for superior image fidelity and maximum light throughput
  • Not recommended for use in Newtonian reflector or Dobsonian reflector telescopes

For terrestrial or astronomical use, this diagonal produces a right-side-up, non-reversed image with correct daytime orientation Not recommended for use in newtonian reflector or dobsonian reflector telescopes Accepts 1.25" eyepieces, fits in 1.25" focusers Fully coated prisms for superior image fidelity and maximum light throughput

I Agree
We use cookies to enhance and personalise your experience with us by collecting information about the pages you visit and actions taken on the site. More details