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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.

Visual Accessories

Optical accessories are what turn one telescope into several. The same optical tube can be a wide-field imaging refractor, a high-power planetary instrument or a comfortable binocular-view visual scope depending on what you put behind it. David Astro carries a deep selection of eyepieces, diagonals, Barlows, reducers, flatteners, binoviewers and correctors in Canada, held in Canadian stock.

Our team uses this equipment on our own telescopes, so the advice you get is based on what actually works at a given focal ratio and under a given sky, not on a spec sheet. If you are deciding between two focal lengths or wondering whether a corrector will help your optic, ask us before you order.

Filters

$45.00 - $45.00
$45.00
$45.00 - $45.00
$45.00

Celestron Star Diagonal - 1.25"

CEL-94115-A

Provides a comfortable 90° viewing angle Inserts into any 1.25" telescope focuser or visual back Accepts standard 1.25" eyepieces Corrects image o...

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$45.00 - $45.00
$45.00
$45.00 - $45.00
$45.00
$259.95 - $259.95
$259.95
$259.95 - $259.95
$259.95

Celestron Stereo Binocular Viewer

CEL-93691

Engage both eyes for more comfortable, detailed, and higher-contrast celestial views High-quality BAK-4 prisms with a 22mm clear aperture prevent ...

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$259.95 - $259.95
$259.95
$259.95 - $259.95
$259.95
$124.95 - $124.95
$124.95
$124.95 - $124.95
$124.95

Celestron X-Cel LX 2x Barlow - 1.25"

CEL-93529

Doubles the magnification of any 1.25" eyepiece 3-element apochromatic optics for color-accurate, high-contrast views Fully multi-coated lenses ma...

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$124.95 - $124.95
$124.95
$124.95 - $124.95
$124.95
$124.95 - $124.95
$124.95
$124.95 - $124.95
$124.95

Celestron X-Cel LX 3x Barlow - 1.25"

CEL-93428

Triples the magnification of any 1.25" eyepiece 3-element apochromatic optics for superior color correction Fully multi-coated for maximum image c...

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$124.95 - $124.95
$124.95
$124.95 - $124.95
$124.95
$43.01 - $43.01
$43.01
$43.01 - $43.01
$43.01

David Astro 90° Diagonal - 1.25"

DAV-DIAG-1.25
Only 2 left!

The 1.25" Mirror Diagonal is a must-have accessory for astronomers, providing a comfortable viewing angle and improved image quality during telesc...

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$43.01 - $43.01
$43.01
$43.01 - $43.01
$43.01
$109.00 - $109.00
$109.00
$109.00 - $109.00
$109.00

David Astro 99% Dielectric Twist-Lock Diagonal - 1.25"

DAV-DIG-TL-1.25
6 in stock

The 1.25" 99% Dielectric Twist-Lock Diagonal is an essential upgrade for astronomers seeking the best in optical performance and convenience. This...

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$109.00 - $109.00
$109.00
$109.00 - $109.00
$109.00
$159.00 - $159.00
$159.00
$159.00 - $159.00
$159.00

David Astro 99% Dielectric Twist-Lock Diagonal - 2"

DAV-DIG-TL-2
Only 5 left!

The 2" 99% Dielectric Twist-Lock Diagonal is an essential upgrade for astronomers seeking the best in optical performance and convenience. This pre...

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$159.00 - $159.00
$159.00
$159.00 - $159.00
$159.00
$149.00 - $149.00
$149.00
$149.00 - $149.00
$149.00

David Astro Penta Prism Diagonal - 1.25"

DAV-PENTA-1.25
Only 4 left!

The David Astro Penta Prism 90-Degree Diagonal is a non inverting non reversing diagonal. It’s particularly suited for use with the David Astro Pre...

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$149.00 - $149.00
$149.00
$149.00 - $149.00
$149.00
Sold out
$399.00 - $399.00
$399.00
$399.00 - $399.00
$399.00

David Astro Premium Linear Erect Binoviewer

DAV-BINO

No backfocus requirement, it can be used with any telescopes, newtonians included, without the need for barlow or extender lenses. Self-Centering ...

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$399.00 - $399.00
$399.00
$399.00 - $399.00
$399.00
Sold out
Daystar 2" Dielectric Mirror Diagonal
$159.00 - $159.00
$159.00
$159.00 - $159.00
$159.00

Daystar 2" Dielectric Mirror Diagonal

DAY-DS2MD

2.0" Barrel Size Dielectric Mirror Coating For Telescopes with 2" Focusers 90-Degree Viewing Angle Description FAQ Specifications In the Box Wa...

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$159.00 - $159.00
$159.00
$159.00 - $159.00
$159.00
$119.99 - $119.99
$119.99
$119.99 - $119.99
$119.99

Explore Scientific 2x Focal Extender - 1.25"

ES-FE02-125

Doubles the magnification of any 1.25" eyepiece Telecentric optical design ensures a true 2x power factor Maintains the original eye relief of the...

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$119.99 - $119.99
$119.99
$119.99 - $119.99
$119.99
$179.99 - $179.99
$179.99
$179.99 - $179.99
$179.99

Explore Scientific 2X Focal Extender - 2"

ES-FE02-020

2X Focal Extender 2-inch Barrel with 1.25-inch Adapter Telecentric Optical Design Fully EMD-Coated Optics Edge-Blackened Lens Elements Descript...

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$179.99 - $179.99
$179.99
$179.99 - $179.99
$179.99
$139.99 - $139.99
$139.99
$139.99 - $139.99
$139.99

Explore Scientific 3X Focal Extender - 1.25"

ES-FE03-125
1 in stock

Instantly triples the magnification of any 1.25" eyepiece Telecentric optical design provides consistent magnification Maintains the eye relief of...

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$139.99 - $139.99
$139.99
$139.99 - $139.99
$139.99
$179.99 - $179.99
$179.99
$179.99 - $179.99
$179.99

Explore Scientific 3X Focal Extender - 2"

ES-FE03-020

Provides 3X magnification for any 2" or 1.25" eyepiece Telecentric optical design ensures consistent magnification Fully EMD-coated optics for max...

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$179.99 - $179.99
$179.99
$179.99 - $179.99
$179.99
$129.99 - $129.99
$129.99
$129.99 - $129.99
$129.99

Explore Scientific 5X Focal Extender - 1.25"

ES-FE05-125
2 in stock

Delivers a 5X magnification increase to any 1.25" eyepiece 1.25" barrel diameter fits standard focusers and accessories Telecentric optical design...

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$129.99 - $129.99
$129.99
$129.99 - $129.99
$129.99
$219.99 - $219.99
$219.99
$219.99 - $219.99
$219.99

Explore Scientific 99% Reflective Diagonal -2"

ES-DD02-00CF

2-inch Diagonal Barrel with Tapered Safety Edge 99% Reflectivity from Dielectric Coatings Includes 1.25-inch Eyepiece Adapter Non-Marring Brass Co...

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$219.99 - $219.99
$219.99
$219.99 - $219.99
$219.99
$589.99 - $589.99
$589.99
$589.99 - $589.99
$589.99

Explore Scientific 99% Reflective Diagonal -3"

ES-DD03-01CF

3-inch diagonal body for large format focusers 99% reflectivity from durable dielectric coatings Includes a 2-inch eyepiece adapter with compressi...

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$589.99 - $589.99
$589.99
$589.99 - $589.99
$589.99
Explore Scientific BinoViewer for Telescopes
$499.99 - $499.99
$499.99
$499.99 - $499.99
$499.99

Explore Scientific BinoViewer for Telescopes

ES-BINOV

Engage both eyes for more comfortable, immersive viewing Integrated erecting prism provides correctly oriented images Accepts two matched 1.25" ey...

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$499.99 - $499.99
$499.99
$499.99 - $499.99
$499.99
iOptron Dielectric Star Diagonal (1.25")
$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00

iOptron Dielectric Star Diagonal (1.25")

IOP-6231

1.25" Barrel Diameter Dielectric Mirror Coatings Improves Image Brightness and Contrast Durable, Long-Lasting Reflective Surface Ideal for Refract...

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$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00
iOptron Dielectric Star Diagonal (2'')
$148.00 - $148.00
$148.00
$148.00 - $148.00
$148.00

iOptron Dielectric Star Diagonal (2'')

IOP-6232

2-inch Barrel for Wide-Field Eyepieces Multi-Layer Dielectric Mirror Coatings High-Reflectivity for Brighter Images Enhanced Coating Durability an...

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$148.00 - $148.00
$148.00
$148.00 - $148.00
$148.00
iOptron Universal Smartphone Eyepiece Adapter - Red
$49.00 - $49.00
$49.00
$49.00 - $49.00
$49.00

iOptron Universal Smartphone Eyepiece Adapter - Red

IOP-8432

Universal smartphone clamp for afocal astrophotography Attaches your phone camera to a telescope eyepiece Lightweight design minimizes focuser str...

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$49.00 - $49.00
$49.00
$49.00 - $49.00
$49.00
SVBONY 2X Barlow 1.25inch with M42 Threads
$15.00 - $15.00
$15.00
$15.00 - $15.00
$15.00

SVBONY 2X Barlow Lens with M42 Threads - 1.25"

SV-F9108A
7 in stock

2X Magnification Factor Standard 1.25" Diameter Barrel Integrated M42x0.75 T-Threads for Cameras Multilayer HD Broadband Green Film Coatings Full ...

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$15.00 - $15.00
$15.00
$15.00 - $15.00
$15.00
Svbony Barlow Lens 1.25 inch 5X
$15.29 - $15.29
$15.29
$15.29 - $15.29
$15.29

SVBONY 5X Barlow Lens - 1.25"

SV-F9102A

5X Magnification Power 1.25" (31.7mm) Barrel Size Multi-Coated Optical Glass Durable Metal Housing Weight: 3.0oz (85g) Description FAQ Specific...

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$15.29 - $15.29
$15.29
$15.29 - $15.29
$15.29
Svbony Metal Telescope Cellphone Holder Bracket
$10.62 - $10.62
$10.62
$10.62 - $10.62
$10.62

SVBONY Metal Telescope Cellphone Holder Bracket for 24-38mm Eyepieces

SV-F9112A

Eyepiece Compatibility: 24-38mm Diameter Smartphone Width: 60-95mm 360° Camera Rotation Durable Metal Construction Foam-Padded Phone Protection ...

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$10.62 - $10.62
$10.62
$10.62 - $10.62
$10.62

Choosing Optical Accessories That Match Your Telescope

Every accessory in this collection modifies the light cone before it reaches your eye or sensor. The right choice depends almost entirely on your telescope's focal ratio, focal length and back-focus budget.

  • Eyepieces: Focal length sets magnification against your telescope's focal length; apparent field and eye relief determine how comfortable that magnification is to use.
  • Diagonals: Dielectric mirrors typically exceed 99% reflectivity; prisms can outperform them at f/10 and slower on planetary targets but introduce chromatic effects in fast refractors.
  • Barlow lenses and extenders: Multiply focal length for planetary work and push the focal plane outward, which is often the cheapest fix for a scope that will not reach focus with a diagonal.
  • Field flatteners and reducers: Correct field curvature and coma across large sensors; each has a fixed back-focus that must be hit precisely.
  • Binoviewers: Two-eye viewing that dramatically improves perceived detail on the Moon and planets, at the cost of significant added optical path.
  • Finders and reflex sights: Acquisition optics — the accessory most often skipped and most often missed.

Why Choose David Astro for Optical Accessories

Optics are easy to buy badly. A well-reviewed eyepiece can still be the wrong eyepiece for your focal ratio, exit pupil or sky.

  • Focal length guidance: We help you build a spaced eyepiece set rather than three focal lengths that overlap, and we calculate exit pupil against your aperture and typical seeing.
  • Corrector matching: We confirm that a flattener or reducer is designed for your telescope's focal ratio before you buy, since a mismatched corrector degrades a field rather than fixing it.
  • Authorized dealer: Full manufacturer warranty and verified authenticity on everything we list.
  • Canadian stock: In-stock optics ship from Canada, with no surprise duties or brokerage fees for Canadian customers.
  • Service and support after the sale: In-house diagnostics if something is not performing as expected.

Optical Accessories in Canada — Frequently Asked Questions

Will a premium eyepiece improve a modest telescope?
Usually yes at the edges of the field, especially in fast telescopes below f/6 where simpler designs struggle. On the axis at f/10, the difference between a good eyepiece and a premium one is much smaller.
How do I know if I need a flattener or a reducer?
A flattener corrects curvature at the same focal length. A reducer also shortens focal length, widening the field and speeding the system. If your stars are elongated only in the corners, you need a flattener; if you also want more field, a reducer.
Do binoviewers work in every telescope?
They add roughly 100 mm or more of optical path, so most refractors need a corrector or a Barlow-style element to reach focus. Schmidt-Cassegrains generally accommodate them without modification.
Is everything shipped domestically?
Yes. Anything shown as in stock is held in Canada and ships without customs delays for Canadian orders.

Match the accessory to the optic

Tell us your telescope and what you want to see, and we will recommend the right combination. Ships from Canada.