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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 $38.00 - Original price $38.00
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Baader Adapter - S52/M48

BAA-2958552

Adapts the Baader S52 dovetail interface to a standard M48 female thread (2" filter thread) Designed specifically for Baader Protective and standa...

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Original price $38.00 - Original price $38.00
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Current price $38.00
Original price $48.00 - Original price $48.00
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$48.00
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Current price $48.00

Baader Adapter - Vixen M43x1/T-2

BAA-1508037

Connects Vixen M43x1 female threads to the T-2 (M42x0.75) system Unlocks compatibility with T-rings, filter wheels, and cameras Machined by Baader...

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Original price $48.00 - Original price $48.00
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Original price $49.00 - Original price $49.00
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Baader Adapter - Zeiss M44(F)/T-2(F)

BAA-1508041

Connects female Zeiss M44 threads to female T-2 threads Integrates legacy Zeiss optics with the modern Baader Astro T-2 System Enables the use of ...

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Original price $49.00 - Original price $49.00
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Original price $52.00 - Original price $52.00
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Baader Adapter 2" SCT(F) Thread/T-2(M)

BAA-2958244
1 in stock

Adapts female 2" SCT threads to male T-2 (M42x0.75) threads Ultra-low profile design minimizes optical path length Single-piece construction ensur...

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Original price $52.00 - Original price $52.00
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Original price $39.00 - Original price $39.00
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Baader Adapter 2" SCT(M) Thread/T-2(M)

BAA-2958242

Connects T-2 (M42x0.75) accessories to 2" SCT rear threads Adds only 1mm of optical path length to the imaging train Male 2" SCT thread (2"-24 TPI...

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Original price $39.00 - Original price $39.00
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Original price $176.00 - Original price $176.00
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$176.00
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Baader Adapter Combination - 3.3" SCT(F)/M68x1(M)

BAA-2458216

Connects 3.3" Celestron/Meade female SCT threads to male M68x1 threads Adds a minimal 11.5mm of optical path length to the imaging train Enables t...

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Original price $176.00 - Original price $176.00
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Original price $71.00 - Original price $71.00
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Baader Adapter for Baader Wide T-Ring - S52/M68

BAA-2458252

Connects S52 Baader Wide T-Rings to M68 Accessories Creates a Rigid, Fully Threaded Connection Maintains Maximum Clear Aperture to Prevent Vignett...

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Original price $71.00 - Original price $71.00
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Original price $33.95 - Original price $33.95
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Baader Adapter M54i to M48a

BAA-2958750

Converts Female M54 Thread (M54i) Provides Male M48 Thread (M48a) Enables Connection of 2" Filter Thread Accessories Low-Profile Mechanical Design...

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Original price $33.95 - Original price $33.95
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Sold out
Original price $32.00 - Original price $32.00
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Baader Budget Eyepiece Clamp -1.25"/T-2

BAA-2458120
1 in stock

Adapts T-2 (M42x0.75) Threads to a 1.25" Eyepiece Holder Provides a Standard 1.25" Receptacle for Eyepieces and Accessories Part of the Baader Ast...

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Original price $32.00 - Original price $32.00
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Original price $68.00 - Original price $68.00
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Baader C to T-2 Mount w/ Integrated Filter Holder

BAA-2958520

Connects C-Mount cameras to T-2 thread accessories Integrated holder for a single filter Accepts both standard mounted and unmounted filters Minim...

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Original price $68.00 - Original price $68.00
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Original price $54.00 - Original price $54.00
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Baader C-Mount/T-2 Extension Ring

BAA-2958521

Connects female 1" C-mount threads to male T-2 threads Adapts industrial, scientific, and video cameras to astronomical accessories Functions as a...

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Original price $54.00 - Original price $54.00
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Original price $48.00 - Original price $48.00
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Baader Camera Adapter - M42x1(F)/T-2 (M)

BAA-1508015

Female Thread: M42x1 (Russian Standard) Male Thread: T-2 (M42x0.75) Connects Russian Optics to T-2 Accessories Enables Use of 1¼" Eyepiece Holders...

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Original price $48.00 - Original price $48.00
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Original price $126.00 - Original price $126.00
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Baader Celestron Nut - 3.3" SCT Thread

BAA-2408145

Adapts the large 3.3" SCT rear thread for the Baader T-2 accessory system Provides a rigid, all-threaded connection for astrophotography Compatibl...

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Original price $126.00 - Original price $126.00
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Original price $235.00 - Original price $235.00
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Baader Changer to fit Carl Zeiss Adapter System (Dovetail Clamp Only) -M68/S68

BAA-2458180

Connects Baader M68 System to Zeiss S68 Dovetails Creates a Secure, Zero-Flexure Threaded Connection Designed for Professional Astrophotography an...

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Original price $235.00 - Original price $235.00
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Original price $98.00 - Original price $98.00
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Baader ClickLock Adapter - 1.25"/2"

BAA-2956214
1 in stock

Adapts 2" focusers and diagonals to accept 1.25" accessories ClickLock cam-lever mechanism for secure, rapid clamping Thumbscrew-free design preve...

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Original price $98.00 - Original price $98.00
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Original price $109.00 - Original price $109.00
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Baader ClickLock Eyepiece Clamp - 1.25"/T-2

BAA-2458100
1 in stock

Securely Clamps 1.25" Eyepieces and Accessories Replaces Thumbscrews with a Simple Twist-Lock Action T-2 Female Thread (Telescope Side) for System...

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Original price $109.00 - Original price $109.00
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Original price $106.00 - Original price $237.00
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Baader ClickLock Eyepiece Clamps - from T-2 to 4.1"

Options available
14 variants in stock

Replaces standard thumbscrew holders with a secure twist-lock mechanism Ensures perfect axial alignment for eyepieces and cameras Provides a solid...

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Original price $106.00 - Original price $237.00
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Original price $73.00 - Original price $73.00
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Baader Conversion Ring - M68x1(F)/M68x1(F)

BAA-2458195

Converts any male M68x1 thread into a female M68x1 thread Features female M68x1 threads on both sides Enables direct connection between two male-t...

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Original price $73.00 - Original price $73.00
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Original price $88.00 - Original price $88.00
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Baader Conversion Ring - M68x1(M)/2"UNF(F)

BAA-2458232

Adapts male M68x1 threads to female 2" UNF threads Enables the use of standard 2" mounted filters Part of the Baader M68 thread system Machined fo...

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Original price $88.00 - Original price $88.00
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Original price $72.00 - Original price $72.00
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Baader Conversion Ring - M68x1(M)/M68x1(M)

BAA-2458194

Converts M68 Female (Internal) Threads to M68 Male (External) Male M68x1 Thread on Both Sides Enables Rigid Connection Between Two Female M68 Port...

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Original price $72.00 - Original price $72.00
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Original price $83.00 - Original price $83.00
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Baader Conversion Ring - M68x1(M)/T-2(M)

BAA-2458233

Connects M68x1 threaded components to T-2 accessories Converts a male M68x1 thread to a male T-2 (M42x0.75) thread Enables connection of cameras, ...

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Original price $83.00 - Original price $83.00
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Original price $70.00 - Original price $70.00
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Baader Conversion Ring Zeiss to Hex Focusers - M68x0.75(F)/M68x1(F)

BAA-2458236

Adapts M68x0.75 male threads to accept M68x1 male accessories Internal Thread 1: M68x1 (Zeiss Standard) Internal Thread 2: M68x0.75 Designed for f...

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Original price $70.00 - Original price $70.00
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Original price $71.00 - Original price $71.00
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Current price $71.00

Baader Deluxe Clamping Eyepiece Holder - 2"

BAA-2408140

Securely holds all 2" eyepieces and accessories Non-marring clamping mechanism prevents scratches on barrels Ensures precise and repeatable center...

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Original price $71.00 - Original price $71.00
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Current price $71.00
Original price $77.00 - Original price $77.00
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Current price $77.00

Baader Diascope Bayonet Eyepiece Adapter - 1.25"

BAA-2454500

Adapts Zeiss Diascope Bayonet to a standard 1.25" eyepiece holder Unlocks access to the entire 1.25" astronomical eyepiece market Enables use of s...

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Original price $77.00 - Original price $77.00
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Current price $77.00

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.