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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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$81.00 - $81.00
$81.00
$81.00 - $81.00
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Baader Q-Turret Quad Eyepiece Revolver - 1.25"

BAA-2957010
1 in stock

Holds four 1.25" eyepieces for rapid switching Lightweight design is compatible with most focusers Metal threads for secure connections Accepts pl...

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$81.00 - $81.00
$81.00
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$136.00 - $136.00
$136.00
$136.00 - $136.00
$136.00

Baader Steel Change Ring to fit Zeiss Adapter System (Dovetail-Ring Only) - M68/S68

BAA-2458185

Connects Baader M68 System to Zeiss S68 Dovetail All-Steel Construction for Maximum Rigidity Eliminates Flexure and Tilt in Imaging Trains Enables...

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$136.00 - $136.00
$136.00
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$41.00 - $41.00
$41.00
$41.00 - $41.00
$41.00

Baader Stop-Ring -1.25"

BAA-1905131

Sets a repeatable, precise focus position for any 1.25" accessory Ideal for parfocalizing a set of eyepieces Reduces time spent refocusing when sw...

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$41.00 - $41.00
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$41.00
$45.00 - $45.00
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$45.00

Baader T-2 Conversion Ring - 10mm T-2(F)/T-2(F)

BAA-2958110

10mm Fixed Extension Length T-2 Female to T-2 Female Threads Part of the Baader T-2 Astro System Joins Two Male T-2 Threaded Accessories Precision...

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$45.00 - $45.00
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$19.00 - $19.00
$19.00
$19.00 - $19.00
$19.00

Baader T-2 Delrin Spacer Ring Set - 15pc

BAA-2458102
1 in stock

Set of 15 Spacer Rings Includes 5 Different Thicknesses (0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm) 3 Rings of Each Size Enables Rotational "Clocking" of ...

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$19.00 - $19.00
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$19.00
$35.00 - $35.00
$35.00
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$35.00

Baader T-2 Extension Tube- 15mm

BAA-1508154
1 in stock

Adds a fixed 15mm of optical path length Standard T-2 (M42x0.75) male and female threads Precision-machined for accurate, repeatable spacing Matte...

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$35.00 - $35.00
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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Baader T-2 Extension Tube- 40mm

BAA-1508153
1 in stock

Adds exactly 40mm of optical path length Standard T-2 (M42x0.75) male and female threads Provides rigid, non-flexing spacing for astrophotography ...

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$39.00 - $39.00
$39.00
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$32.00 - $32.00
$32.00
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$32.00

Baader T-2 Extension Tube- 7.5mm

BAA-1508155
1 in stock

Adds 7.5mm of fixed optical path length Part of the modular Baader T-2 Astro System Standard T-2 (M42x0.75) internal and external threads Precisio...

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$32.00 - $32.00
$32.00
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$9.00 - $27.00
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$9.00

Baader T-2 Fine-Adjustment Aluminum Ring - 0.3/0.5/1mm

Options available
2 variants in stock

Precision T-2 thread shims for rotational alignment Available in 0.3mm, 0.5mm, and 1.0mm thicknesses Ultra-thin design minimizes impact on back fo...

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$9.00 - $27.00
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$47.00 - $47.00
$47.00
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$47.00

Baader T-2 Inverter Ring - T-2(M)/T-2(M)

BAA-1508025

Connects Two Female T-2 Threaded Accessories Provides a Male-to-Male T-2 Bridge Low-Profile Design Minimizes Added Length Part of the Baader Astro...

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$47.00 - $47.00
$47.00
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$31.00 - $31.00
$31.00
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$31.00

Baader T-2 Locking Ring (2mm length)

BAA-2958120

Adds a precise 2mm of optical path length Enables full 360° rotational adjustment for cameras and accessories Locks components securely at any ori...

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$31.00 - $31.00
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$31.00
$55.00 - $55.00
$55.00
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$55.00

Baader T-2 Quick Change Ring

BAA-2456320
1 in stock

Enables rapid accessory changes without unthreading Part of the comprehensive Baader T-2 Astro-System Precision-machined for a secure, non-marring...

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$55.00 - $55.00
$55.00
$55.00 - $55.00
$55.00
$66.00 - $66.00
$66.00
$66.00 - $66.00
$66.00

Baader T-2 Quick Changer

BAA-2456313
1 in stock

Enables rapid accessory changes Secure locking mechanism Full integration with the Baader T-2 system Maintains optical alignment between swaps Red...

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$66.00 - $66.00
$66.00
$66.00 - $66.00
$66.00
$90.00 - $90.00
$90.00
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$90.00

Baader T-Adapter for SCT & Maks - 2" SCT(F) Thread/T-2(M)

BAA-2408160
1 in stock

Connects standard 2-inch SCT/MAK rear cells to T-2 accessories Short, compact profile minimizes consumption of precious back focus Enables the use...

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$90.00 - $90.00
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$41.00 - $41.00
$41.00
$41.00 - $41.00
$41.00

Baader T-Ring Canon EF (EOS) - T-2

BAA-2408319
1 in stock

Connects Canon EF (EOS) mount cameras to T-2 threads Enables prime-focus astrophotography Precision-machined for a secure, no-flex connection Inte...

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$41.00 - $41.00
$41.00
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$41.00
$59.00 - $59.00
$59.00
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$59.00

Baader T-Ring Canon EOS - UltraShort T-2

BAA-2408318
1 in stock

Ultra-Short Optical Path to Maximize Back Focus Connects Canon EOS Cameras to T-2 (M42x0.75) Threads Enables Focus with Reducers, Correctors, and ...

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$59.00 - $59.00
$59.00
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$59.00
$41.00 - $41.00
$41.00
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$41.00

Baader T-Ring Micro Four Thirds (4/3) - T-2 w/ 19mm Extension

BAA-2408330
1 in stock

Connects Micro Four Thirds (4/3) cameras to any T-2 threaded accessory Includes a 19mm T-2 extension tube for precise back focus spacing Enables s...

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$41.00 - $41.00
$41.00
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$39.00 - $39.00
$39.00
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$39.00

Baader T-Ring Nikon - T-2

BAA-2408300
1 in stock

Connects Nikon F-Mount Cameras to T-2 Threads (M42x0.75) Enables Prime-Focus Astrophotography Precision-Machined for a Secure, No-Flexure Fit Inte...

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$39.00 - $39.00
$39.00
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$45.00 - $45.00
$45.00
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$45.00

Baader T-Ring Sony E/NEX Bayonet - D52/M48 & T-2

BAA-2408317
1 in stock

Connects Sony E/NEX mount cameras to telescopes Ultra-short design adds only 8.3mm of optical length Features three connection standards: T-2, M48...

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$45.00 - $45.00
$45.00
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$45.00
$82.00 - $82.00
$82.00
$82.00 - $82.00
$82.00

Baader Takahashi Adapter - M72/M68

BAA-2558230

Adapts native Takahashi M72 threads to the Baader M68 system Enables creation of an ultra-short 2" eyepiece holder on Takahashi refractors Provide...

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$82.00 - $82.00
$82.00
$82.00 - $82.00
$82.00
$37.00 - $37.00
$37.00
$37.00 - $37.00
$37.00

Baader Takahashi Converter Ring - T-2(M)/M43x0.75

BAA-2458199

Adapts Takahashi M43x0.75 female threads to a male T-2 (M42x0.75) thread Unlocks compatibility with the Baader Astro T-2 System Enables direct att...

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$37.00 - $37.00
$37.00
$37.00 - $37.00
$37.00
$73.00 - $73.00
$73.00
$73.00 - $73.00
$73.00

Baader Takahashi Mewlon Aux-Adapter - M71/M72

BAA-2558231

Adapts M71 Female Thread to M72 Female Thread Designed for Takahashi Mewlon Reflectors Enables Secure, Flexure-Free Accessory Attachment Integral ...

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$73.00 - $73.00
$73.00
$73.00 - $73.00
$73.00
$86.00 - $86.00
$86.00
$86.00 - $86.00
$86.00

Baader Takahashi Sky90 Adapter - M64x0.75(M)/M68x1(F)

BAA-2458231

Adapts the Takahashi Sky90's M64x0.75 male thread Provides a robust M68x1 female thread for accessories Enables secure, direct-thread connection f...

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$86.00 - $86.00
$86.00
$86.00 - $86.00
$86.00
$50.00 - $50.00
$50.00
$50.00 - $50.00
$50.00

Baader UFC Camera Side Adapter - 2"(M) SCT Thread

BAA-2459120

Adapts the Baader UFC Base to a male 2" SCT thread Enables connection of SCT-specific focal reducers and accessories Mounts directly to the camera...

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$50.00 - $50.00
$50.00
$50.00 - $50.00
$50.00

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.