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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

$181.00 - $181.00
$181.00
$181.00 - $181.00
$181.00

APM Dielectric Mirror Star Diagonal - 2"

APM-2-diag-DX-FL
Only 2 left!

APM 2 inch star diagonal mirror with 99% di-electric coating with fast-lockThe diagonal mirror is produced by APM-Telescopes with highest qualityOp...

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$181.00 - $181.00
$181.00
$181.00 - $181.00
$181.00
Askar 2” High-Precision Dielectric Diagonal
$175.00 - $175.00
$175.00
$175.00 - $175.00
$175.00

Askar 2” High-Precision Dielectric Diagonal

ASK-ASKAR2DIAG

2-inch Barrel Diameter High-Reflectivity Dielectric Mirror Coating Accepts both 2" and 1.25" Eyepieces Compatible with SCT and Refractor/Reflector...

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$175.00 - $175.00
$175.00
$175.00 - $175.00
$175.00
$289.00 - $289.00
$289.00
$289.00 - $289.00
$289.00

Baader 2" Newton 1.7X Glasspath and Coma Corrector

BAA-2456301

2" Glasspathcorrector®Factor 1.7 for Newtons - at full aperture with integrated Coma-Corrector. Includes T-2 change ring (#2456320) for adaptation...

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$289.00 - $289.00
$289.00
$289.00 - $289.00
$289.00
$230.00 - $230.00
$230.00
$230.00 - $230.00
$230.00

Baader 2" Refractor/SCT 1.8X Glasspath Corrector

BAA-2456305

2" Glasspathcorrector®Factor 1.8 for Refractors and Schmidt Cassegrains - at full aperture. Suitable to insert into the Baader Maxbright and Mark ...

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$230.00 - $230.00
$230.00
$230.00 - $230.00
$230.00
$81.00 - $81.00
$81.00
$81.00 - $81.00
$81.00

Baader 2.25x Q-Barlow - 1.25"

BAA-2956185

Provides 2.25x magnification in its standard 1.25" housing Lens element unscrews for ~1.3x magnification when threaded directly into an eyepiece F...

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$81.00 - $81.00
$81.00
$81.00 - $81.00
$81.00
$266.00 - $266.00
$266.00
$266.00 - $266.00
$266.00

Baader 2x VIP Modular Barlow - 1.25"

BAA-2406101

Modular 2x Barlow Design 1.25" Barrel and Filter Thread Compatibility Integrated T-2 Threads for Imaging Designed for Full-Frame Sensor Illuminati...

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$266.00 - $266.00
$266.00
$266.00 - $266.00
$266.00
$104.00 - $104.00
$104.00
$104.00 - $104.00
$104.00

Baader 45° Amici Prism Diagonal w/ 24mm Clear Aperture - 1.25"

BAA-2956150

Provides a correctly oriented, erect image for terrestrial viewing Comfortable 45° viewing angle Full 24mm clear aperture prevents vignetting with...

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$104.00 - $104.00
$104.00
$104.00 - $104.00
$104.00
$268.00 - $268.00
$268.00
$268.00 - $268.00
$268.00

Baader 45° Amici Prism Diagonal 45° - 2" SCT Thread

BAA-2956151

Provides a fully corrected, upright, and non-reversed image Comfortable 45° viewing angle for terrestrial observation Attaches directly to 2" SCT ...

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$268.00 - $268.00
$268.00
$268.00 - $268.00
$268.00
$806.00 - $806.00
$806.00
$806.00 - $806.00
$806.00

Baader 90° Astro-Grade Amici Prism w/ BBHS Coating - 2" ClickLock

BAA-2456120
1 in stock

Provides a fully corrected, non-reversed and non-inverted image Comfortable 90° viewing angle Full 2-inch clear aperture prevents vignetting Baade...

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$806.00 - $806.00
$806.00
$806.00 - $806.00
$806.00
$358.00 - $358.00
$358.00
$358.00 - $358.00
$358.00

Baader 90° Astro-Grade Amici Prism w/ BBHS Coating - T-2

BAA-2456130
1 in stock

90° comfortable viewing angle Amici prism design provides correctly oriented, erect images Features a full 1.25" clear aperture to prevent vignett...

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$358.00 - $358.00
$358.00
$358.00 - $358.00
$358.00
$335.00 - $335.00
$335.00
$335.00 - $335.00
$335.00

Baader 90° Erecting Prism Diagonal - 2"

BAA-2956152

Provides a fully erect, non-reversed image 90° viewing angle for comfortable observing 2" barrel for use with large focusers Includes a 2" to 1.25...

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$335.00 - $335.00
$335.00
$335.00 - $335.00
$335.00
$181.00 - $181.00
$181.00
$181.00 - $181.00
$181.00

Baader 90° Prism Diagonal w/ 32mm Prism - T-2

BAA-2456005
1 in stock

90° comfortable viewing angle Large 32mm prism for full field illumination Baader T-2 thread system for modular connections Maxbright-series prism...

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$181.00 - $181.00
$181.00
$181.00 - $181.00
$181.00
$217.00 - $217.00
$217.00
$217.00 - $217.00
$217.00

Baader 90° Zenith Prism Diagonal w/ 32mm Prism - 1.25"

BAA-2456005K
1 in stock

90° Zenith Prism Diagonal Oversized 32mm Prism 1.25" Barrel Format Baader T-2 System Threads Includes 1.25" Eyepiece Holder & Nosepiece Des...

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$217.00 - $217.00
$217.00
$217.00 - $217.00
$217.00
$14.00 - $14.00
$14.00
$14.00 - $14.00
$14.00

Baader Auxillary-Ring for Adaptation of MaxBright II

BAA-2458272

Creates the shortest possible connection for a MaxBright II Binoviewer Designed for direct attachment to any Baader T-2 star diagonal Prevents uni...

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$14.00 - $14.00
$14.00
$14.00 - $14.00
$14.00
$559.00 - $559.00
$559.00
$559.00 - $559.00
$559.00

Baader BBHS Prism Adjustable Star Diagonal - 2"

BAA-2456118
1 in stock

Broad Band Hard Silver (BBHS®) Coated Prism 2-inch ClickLock® Self-Centering Eyepiece Clamp Fully User-Collimatable Prism Mount CNC-Machined Alumi...

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$559.00 - $559.00
$559.00
$559.00 - $559.00
$559.00
$545.00 - $545.00
$545.00
$545.00 - $545.00
$545.00

Baader Carl Zeiss 2x Abbe Barlow Lens - 1.25" w/ ClickLock

BAA-1603321

2x Nominal Magnification Factor Legendary Carl Zeiss Abbe Optical Design Multi-Layer Coatings with 0.2% Reflection Loss 1.25" Baader ClickLock Eye...

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$545.00 - $545.00
$545.00
$545.00 - $545.00
$545.00
$349.00 - $349.00
$349.00
$349.00 - $349.00
$349.00

Baader FlipMirror II Star Diagonal

BAA-2458055

Instantly switch between three different instrument ports Straight-through port for primary camera or spectrograph 90° mirrored port for visual ob...

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$349.00 - $349.00
$349.00
$349.00 - $349.00
$349.00
$873.00 - $873.00
$873.00
$873.00 - $873.00
$873.00

Baader Fluorite Flatfield Converter

BAA-2458200

Genuine Calcium Fluorite (CaF2) Two-Element Cemented Design Corrects for Field Curvature to Produce a Flat Imaging Plane Variable Magnification Fa...

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$873.00 - $873.00
$873.00
$873.00 - $873.00
$873.00
$144.00 - $155.00
$144.00 - $155.00
$144.00 - $155.00
$144.00

Baader Glasspath Corrector for Maxbright Bino and Mark V

Options available
1 variants in stock

Corrects for insufficient back focus to allow binoviewer use Available in 1.25x, 1.7x, and 2.6x magnification factors Removes prism-induced chroma...

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$144.00 - $155.00
$144.00 - $155.00
$144.00 - $155.00
$144.00
$194.00 - $194.00
$194.00
$194.00 - $194.00
$194.00

Baader Hyperion Zoom 2.25X Barlow

BAA-2956180
1 in stock

2.25x Primary Magnification Factor Modular Design with 1.3x Low-Power Configuration Integrated T-2 Thread for Direct Camera Connection Variable 2....

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$194.00 - $194.00
$194.00
$194.00 - $194.00
$194.00
$157.00 - $157.00
$157.00
$157.00 - $157.00
$157.00

Baader Maxbright Amici Prism 1.25"w/ Integral 2X Glasspath Corrector

BAA-2956155

Provides a fully corrected, erect image for terrestrial viewing Designed for the Baader Maxbright Binoviewer Standard 1.25" barrel format Integrat...

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$157.00 - $157.00
$157.00
$157.00 - $157.00
$157.00
$731.00 - $903.00
$731.00 - $903.00
$731.00 - $903.00
$731.00

Baader MaxBright II Binoviewer Set

Options available

Modular design based on the Baader T-2 thread system Optional Glasspath Correctors provide 1.25x, 1.7x, and 2.6x magnification Accommodates both 1...

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$731.00 - $903.00
$731.00 - $903.00
$731.00 - $903.00
$731.00
$279.00 - $279.00
$279.00
$279.00 - $279.00
$279.00

Baader Maxbright Mirror Diagonal - T-2

BAA-2456100
1 in stock

Features Baader's T-2 System threads for full modularity High-reflectivity Maxbright mirror for bright, high-contrast views All-metal housing for ...

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$279.00 - $279.00
$279.00
$279.00 - $279.00
$279.00
$72.00 - $72.00
$72.00
$72.00 - $72.00
$72.00

Baader Microstage II Digiscoping Adapter

BAA-2450330
1 in stock

Enables afocal projection imaging with compact digital cameras Clickstop swing-away arm for rapid switching between viewing and imaging Broad eyep...

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$72.00 - $72.00
$72.00
$72.00 - $72.00
$72.00

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.