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Adapters

Almost every imaging train problem in astrophotography — soft corners, elongated stars, a camera that will not come to focus — traces back to a few millimetres of the wrong adapter. David Astro carries adapters in Canada covering M42, M48, M54, M68, SCT and Nikon and Canon bayonet standards, along with barrel adapters in 1.25" and 2", all in stock and shipping from Canada.

Adapters are the one product category where buying blind is genuinely expensive. Our team calculates back-focus and thread compatibility for customers every day, so before you assemble a stack from guesswork, send us your components and we will specify the parts.

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Original price CA$260.00 - Original price CA$260.00
Original price
CA$260.00
CA$260.00 - CA$260.00
Current price CA$260.00

Askar Focal Plane Adjuster

ASK-ASKARFPA

Corrects focal plane tilt without altering back focus Maintains a constant 18mm optical thickness Provides a ±1° adjustment range Features M54 fem...

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Original price CA$260.00 - Original price CA$260.00
Original price
CA$260.00
CA$260.00 - CA$260.00
Current price CA$260.00
Original price CA$23.00 - Original price CA$23.00
Original price
CA$23.00
CA$23.00 - CA$23.00
Current price CA$23.00

Askar M42-M48 Photo Adapter for FMA180

ASK-ASKARM4248

Connects M48 (2-inch) accessories to the Askar FMA180 Converts the native M42x0.75 T-thread to a larger M48x0.75 thread Engineered for a precise f...

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Original price CA$23.00 - Original price CA$23.00
Original price
CA$23.00
CA$23.00 - CA$23.00
Current price CA$23.00
Original price CA$199.00 - Original price CA$199.00
Original price
CA$199.00
CA$199.00 - CA$199.00
Current price CA$199.00

Askar M54/M48 Backfocus Adjuster

ASK-ASKARBA48
1 in stock

Provides ±2mm of fine backfocus adjustment Total optical length adjustable from 16mm to 20mm High-precision 0.05mm increments Available with M54 o...

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Original price CA$199.00 - Original price CA$199.00
Original price
CA$199.00
CA$199.00 - CA$199.00
Current price CA$199.00
Original price CA$60.00 - Original price CA$60.00
Original price
CA$60.00
CA$60.00 - CA$60.00
Current price CA$60.00

Askar M54/M48 T-Ring for Canon EOS-R

ASK-ASKADA54CA
1 in stock

Securely adapts Canon EOS-R mirrorless camera bodies Connects to M54x0.75 and M48x0.75 threaded correctors Integrated rotational adjuster for fine...

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Original price CA$60.00 - Original price CA$60.00
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CA$60.00
CA$60.00 - CA$60.00
Current price CA$60.00
Original price CA$117.00 - Original price CA$117.00
Original price
CA$117.00
CA$117.00 - CA$117.00
Current price CA$117.00

Baader Complete T-2 Changer System

BAA-2456321
2 in stock

Enables rapid swapping of T-2 threaded accessories Maintains precise rotational alignment between changes Secure locking mechanism prevents tilt a...

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Original price CA$117.00 - Original price CA$117.00
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CA$117.00
CA$117.00 - CA$117.00
Current price CA$117.00
Original price CA$46.00 - Original price CA$46.00
Original price
CA$46.00
CA$46.00 - CA$46.00
Current price CA$46.00

Baader Ultrashort Clamp - 1.25"/T-2

BAA-2458121
1 in stock

Connects 1.25" accessories to T-2 threads Ultrashort design minimizes optical path length Ideal for complex imaging trains with limited back focus...

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Original price CA$46.00 - Original price CA$46.00
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CA$46.00
CA$46.00 - CA$46.00
Current price CA$46.00
Original price CA$132.00 - Original price CA$132.00
Original price
CA$132.00
CA$132.00 - CA$132.00
Current price CA$132.00

Baader Ultrashort Eyepiece Clamp - 2"/M68x1(M)/M60x0.75(M)

BAA-2458196

Securely holds 2" eyepieces and accessories Ultra-low profile design minimizes backfocus consumption Features male M68x1 Zeiss-system threads on b...

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Original price CA$132.00 - Original price CA$132.00
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CA$132.00
CA$132.00 - CA$132.00
Current price CA$132.00
Original price CA$57.00 - Original price CA$57.00
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CA$57.00
CA$57.00 - CA$57.00
Current price CA$57.00

Baader 1" C-Mount Adapter w/ 1.25" Nosepiece - 18mm Long

BAA-2958515

Connects C-Mount (1") cameras to 1.25" focusers Adds a fixed 18mm of optical length Internal threads accept standard 1.25" mounted filters Include...

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Original price CA$57.00 - Original price CA$57.00
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CA$57.00
CA$57.00 - CA$57.00
Current price CA$57.00
Original price CA$133.00 - Original price CA$133.00
Original price
CA$133.00
CA$133.00 - CA$133.00
Current price CA$133.00

Baader 2" Four-in-One Clamp Adapter M68 (Zeiss)/2.7" (A.P.)/M60 (Vixen)/M56 (Synta)

BAA-2458190
1 in stock

Adapts four major large-format focusers to a 2" clamp Female threads: M68 (Zeiss), 2.7" (Astro-Physics) Female threads: M60 (Vixen), M56 (Synta/Sk...

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Original price CA$133.00 - Original price CA$133.00
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CA$133.00
CA$133.00 - CA$133.00
Current price CA$133.00
Original price CA$70.00 - Original price CA$70.00
Original price
CA$70.00
CA$70.00 - CA$70.00
Current price CA$70.00

Baader 2" Locking Ring for SCTs 8"/9.25"/11"/14"

BAA-2458270
1 in stock

Direct-threads to the rear cell of Schmidt-Cassegrain telescopes Compatible with 8", 9.25", 11", and 14" SCT models Designed for Baader 2" zenith ...

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Original price CA$70.00 - Original price CA$70.00
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CA$70.00
CA$70.00 - CA$70.00
Current price CA$70.00
Original price CA$66.00 - Original price CA$66.00
Original price
CA$66.00
CA$66.00 - CA$66.00
Current price CA$66.00

Baader 2" Nosepiece to T-2/M48a – with Safety-Kerf

BAA-2458130
1 in stock

Connects T-2 and M48 accessories to a standard 2-inch focuser Features a modern, shallow T-2 thread depth for new cameras Dual male threads: T-2 (...

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Original price CA$66.00 - Original price CA$66.00
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CA$66.00
CA$66.00 - CA$66.00
Current price CA$66.00
Original price CA$44.00 - Original price CA$44.00
Original price
CA$44.00
CA$44.00 - CA$44.00
Current price CA$44.00

Baader 2"/2" Inverter Ring

BAA-2958243
1 in stock

2-inch Female Thread (Both Sides) Couples Accessories with Male 2-inch Threads Solves Incompatible Gender Connections Ensures a Rigid, Threaded Li...

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Original price CA$44.00 - Original price CA$44.00
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CA$44.00
CA$44.00 - CA$44.00
Current price CA$44.00
Original price CA$46.00 - Original price CA$46.00
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CA$46.00
CA$46.00 - CA$46.00
Current price CA$46.00

Baader 2"/2" Inverter Ring w/ 48mm Filter Thread

BAA-1508020
1 in stock

Creates a direct 2" male thread connection on Baader diagonals Replaces the standard 2" ClickLock eyepiece clamp Solves critical backfocus/in-trav...

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Original price CA$46.00 - Original price CA$46.00
Original price
CA$46.00
CA$46.00 - CA$46.00
Current price CA$46.00
Original price CA$59.00 - Original price CA$59.00
Original price
CA$59.00
CA$59.00 - CA$59.00
Current price CA$59.00

Baader Adapter - 1.25"/0.965"

BAA-2408191

Adapts 1.25" (1¼") focusers to accept 0.965" (24.5mm) eyepieces Brings classic and vintage eyepieces into use with modern telescopes Precision-mac...

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Original price CA$59.00 - Original price CA$59.00
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CA$59.00
CA$59.00 - CA$59.00
Current price CA$59.00
Original price CA$67.00 - Original price CA$67.00
Original price
CA$67.00
CA$67.00 - CA$67.00
Current price CA$67.00

Baader Adapter - 1.25"/2"" w/ T-2 Thread

BAA-2408190

Reduces a 2" focuser to accept 1.25" accessories Features an external male T-2 thread for direct camera attachment Non-marring brass compression r...

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Original price CA$67.00 - Original price CA$67.00
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CA$67.00
CA$67.00 - CA$67.00
Current price CA$67.00
Original price CA$79.00 - Original price CA$79.00
Original price
CA$79.00
CA$79.00 - CA$79.00
Current price CA$79.00

Baader Adapter - 2" NexStar 4 (C90)/ETX

BAA-2958500

Connects Celestron C90/NexStar 4 and Meade ETX telescopes to 2" accessories Enables the use of 2" diagonals for wider true fields of view Accepts ...

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Original price CA$79.00 - Original price CA$79.00
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CA$79.00
CA$79.00 - CA$79.00
Current price CA$79.00
Original price CA$60.00 - Original price CA$60.00
Original price
CA$60.00
CA$60.00 - CA$60.00
Current price CA$60.00

Baader Adapter - 2" SCT(M) Thread/T-2(M)

BAA-1508035

Connects 2" SCT Male Threads to T-2 (M42x0.75) Male Threads Features Internal Threads for Standard 2" Mounted Filters Integrates Filtration Direct...

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Original price CA$60.00 - Original price CA$60.00
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CA$60.00
CA$60.00 - CA$60.00
Current price CA$60.00
Original price CA$271.00 - Original price CA$271.00
Original price
CA$271.00
CA$271.00 - CA$271.00
Current price CA$271.00

Baader Adapter - FLI Dovetail/M68x1(M)

BAA-2458219

Connects FLI Dovetail Mounts to M68x1 Threads Provides a Male (External) M68x1 Thread Enables Integration with Baader M68 Accessories Precision-Ma...

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Original price CA$271.00 - Original price CA$271.00
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CA$271.00
CA$271.00 - CA$271.00
Current price CA$271.00
Original price CA$33.00 - Original price CA$33.00
Original price
CA$33.00
CA$33.00 - CA$33.00
Current price CA$33.00

Baader Adapter - M36.4(M)/T-2(M)

BAA-1508039

Connects Vixen M36.4 Female Threads to T-2 Female Threads Side 1: Male M36.4 x 1.0 Thread (Vixen Standard) Side 2: Male T-2 (M42 x 0.75) Thread En...

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Original price CA$33.00 - Original price CA$33.00
Original price
CA$33.00
CA$33.00 - CA$33.00
Current price CA$33.00
Original price CA$37.00 - Original price CA$37.00
Original price
CA$37.00
CA$37.00 - CA$37.00
Current price CA$37.00

Baader Adapter - M48/T-2

BAA-2958553

Adapts M48 (female) threads to T-2 (male) threads Connects 2-inch accessories to standard camera T-Rings Part of the Baader Astro T-2 System Preci...

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Original price CA$37.00 - Original price CA$37.00
Original price
CA$37.00
CA$37.00 - CA$37.00
Current price CA$37.00
Original price CA$72.00 - Original price CA$72.00
Original price
CA$72.00
CA$72.00 - CA$72.00
Current price CA$72.00

Baader Adapter - M68x1(F)/AP 2.7"(F)

BAA-2458221

Connects Baader M68x1 threaded accessories to Astro-Physics 2.7" focusers Features M68x1 male (external) threads Features Astro-Physics 2.7" femal...

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Original price CA$72.00 - Original price CA$72.00
Original price
CA$72.00
CA$72.00 - CA$72.00
Current price CA$72.00
Original price CA$70.00 - Original price CA$70.00
Original price
CA$70.00
CA$70.00 - CA$70.00
Current price CA$70.00

Baader Adapter - M68x1(F)/AP 2.7"(M)

BAA-2458220

Connects Baader M68x1 Female Threads to AP 2.7" Male Threads Creates a Rigid, Non-Flexing Connection for Imaging Precision-Machined for Secure Opt...

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Original price CA$70.00 - Original price CA$70.00
Original price
CA$70.00
CA$70.00 - CA$70.00
Current price CA$70.00
Original price CA$83.00 - Original price CA$83.00
Original price
CA$83.00
CA$83.00 - CA$83.00
Current price CA$83.00

Baader Adapter - M68x1(F)/M63x1(M) (Feather Touch 2.5", TS-Optics)

BAA-2458239

Connects M68 accessories to M63 focusers Female Thread: M68x1 Male Thread: M63x1 Designed for 2.5" Feather Touch and select TS-Optics focusers Cre...

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Original price CA$83.00 - Original price CA$83.00
Original price
CA$83.00
CA$83.00 - CA$83.00
Current price CA$83.00
Original price CA$67.00 - Original price CA$67.00
Original price
CA$67.00
CA$67.00 - CA$67.00
Current price CA$67.00

Baader Adapter - M68x1(F)/M74x1(F) (Skywatcher Esprit, TS-Optics, Omegon)

BAA-2458237

Converts M74x1 female thread to M68x1 female thread Designed for Skywatcher Esprit, TS-Optics, and Omegon telescopes Provides a rigid, single-piec...

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Original price CA$67.00 - Original price CA$67.00
Original price
CA$67.00
CA$67.00 - CA$67.00
Current price CA$67.00

Understanding Thread Standards and Back-Focus

An adapter does two things at once: it changes the connection type, and it changes the distance between your corrector and your sensor. The second effect is the one that causes trouble, because most reducers and flatteners have a back-focus tolerance of about one millimetre.

  • M42 (T-thread, 0.75 mm pitch): The long-standing standard for camera adapters. Its clear aperture will vignette sensors larger than APS-C, so full-frame imaging trains should avoid it.
  • M48 (2" thread, 0.75 mm pitch): The practical choice for APS-C and full-frame sensors, with enough clear aperture to avoid mechanical vignetting.
  • M54 and M68: Larger-diameter threads used by heavier astrographs and larger-format correctors where rigidity and aperture both matter.
  • SCT 2"-24 TPI: The rear-cell thread on Schmidt-Cassegrains; requires a specific adapter to reach M42 or M48 for imaging.
  • Bayonet adapters: Canon EF and Nikon F adapters place a DSLR or mirrorless body at the correct flange distance, typically 44 mm and 46.5 mm respectively.
  • Fine-tuning spacers: 0.5 mm, 1 mm and 2 mm shims that let you land exactly on a corrector's specified spacing rather than near it.

Why Choose David Astro for Adapters

An adapter is a cheap part that determines whether an expensive telescope performs. We treat it that way.

  • Free back-focus calculation: Give us your camera, filter thickness, reducer and telescope and we will return a component list with the total spacing worked out.
  • Filter thickness accounted for: Glass in the light path shifts focus by roughly one third of its thickness, and we include that in the calculation rather than leaving you to discover it.
  • Male and female threads identified: We specify the gender and standard on both ends, which is the detail most listings omit.
  • Deep Canadian stock: Hundreds of adapters held domestically, so a missing 10 mm spacer does not cost you three weeks of clear sky.
  • Authorized dealer: Genuine manufacturer parts with full warranty, shipped from Canada without duties for Canadian buyers.

Adapters in Canada — Frequently Asked Questions

How do I calculate my back-focus?
Add your camera's sensor-to-flange distance, any filter wheel or off-axis guider, the filter's optical shift, and every spacer between the camera and the corrector. That total must match the corrector's specified figure, usually 55 mm for a standard reducer.
Should I use M42 or M48?
Use M48 for any sensor larger than APS-C. M42 has enough clear aperture for smaller sensors but will mechanically vignette a full-frame chip regardless of the optics ahead of it.
Do filters change my spacing?
Yes. A filter shifts the focal plane by about one third of its glass thickness. A 3 mm filter adds roughly 1 mm to the effective optical path, which is enough to matter at a 55 mm target.
What if I order the wrong adapter?
Contact us with your setup before ordering and we will confirm the parts. That is a faster path than exchanges, and it is a service we provide free.

Send us your imaging train

We will calculate the spacing and specify every adapter you need. Canadian stock, no guesswork.