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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.

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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SVBONY SV194 Photography Adapter for Nikon Camera w/ F-Mount
$7.99 - $7.99
$7.99
$7.99 - $7.99
$7.99

SVBONY SV194 T2 M42x0.75 Photography Adapter for Nikon

SV-W1077A

Connects Nikon F-Mount cameras to standard T-threads Standard M42x0.75 female threads for wide compatibility Enables prime-focus astrophotography ...

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$7.99 - $7.99
$7.99
$7.99 - $7.99
$7.99
SVBONY SV194 Photography Adapter for Nikon Camera w/ F-Mount
$9.59 - $9.59
$9.59
$9.59 - $9.59
$9.59

SVBONY SV194 Wide 48mm T-Ring Adapter for Nikon F-Mount

SV-W1077B

Connects Nikon F-Mount cameras to M48 (2-inch filter) threads Wide 48mm clear aperture minimizes vignetting on full-frame sensors Precision-machin...

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$9.59 - $9.59
$9.59
$9.59 - $9.59
$9.59
Svbony SV195 T-Ring Adapter EF Mount for Canon EOS DSLR Telescope
$7.99 - $7.99
$7.99
$7.99 - $7.99
$7.99

SVBONY SV195 M42x0.75 T-Ring Adapter for Canon EOS DSLR

SV-W2054A

Connects Canon EOS DSLR cameras to standard telescope T-threads Features a 3-screw mechanism for precise rotational adjustment Allows for fine-tun...

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$7.99 - $7.99
$7.99
$7.99 - $7.99
$7.99
Svbony SV195 T Ring Adapter EF Mount for Canon EOS DSLR Telescope
$9.59 - $9.59
$9.59
$9.59 - $9.59
$9.59

SVBONY SV195 M48x0.75 T-Ring Adapter for Canon EOS DSLR

SV-W2054B

Connects Canon EF/EF-S mount cameras to M48x0.75 threaded accessories 3-screw system allows for precise sensor tilt and orthogonality adjustment M...

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$9.59 - $9.59
$9.59
$9.59 - $9.59
$9.59
SVBONY 1.25" T-Adapter Mount with M42 Threads
$3.64 - $3.64
$3.64
$3.64 - $3.64
$3.64

SVBONY T-Adapter Mount with M42 Threads - 1.25"

SV-F9103A

Connects M42 T-thread cameras to 1.25" focusers Standard M42 x 0.75 male threads Fits any telescope with a 1.25" eyepiece holder Lightweight desig...

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$3.64 - $3.64
$3.64
$3.64 - $3.64
$3.64
Tele Vue 1.25" PowerMate T-Ring Adapter 1
$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00

Tele Vue 1.25" PowerMate T-Ring Adapter

TV-PTR-1250
1 in stock

Connection Side 1: Male T-Thread (M42x0.75) Connection Side 2: Female Thread for 1.25" Powermate Compatibility: Tele Vue 2.5x and 5x 1.25" Powerma...

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$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00
Tele Vue Extension Tube - 2" 2
Tele Vue Extension Tube - 2" 1
$78.00 - $78.00
$78.00
$78.00 - $78.00
$78.00

Tele Vue 2" Extension Tube - 2" Length

TV-X2C-0008

Extension Length: 2 inches (50.8mm) Barrel Diameter: 2 inches Locking Mechanism: Brass clamp ring with single thumbscrew Safety Feature: Undercut ...

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$78.00 - $78.00
$78.00
$78.00 - $78.00
$78.00
Tele Vue Extension Tube - 3.5" 2
Tele Vue Extension Tube - 3.5" 1
$78.00 - $78.00
$78.00
$78.00 - $78.00
$78.00

Tele Vue 2" Extension Tube - 3.5" Length

TV-X3C-0009

Extension Length: 3.5" (89mm) Telescope Connection: 2" Barrel Accessory Connection: 2" Barrel Material: Anodized Aluminum Internal Finish: Matte B...

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$78.00 - $78.00
$78.00
$78.00 - $78.00
$78.00
Tele Vue Eyepiece Barrel Extension - 2" 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue 2" Eyepiece Barrel Extension - 1.2" Length

TV-EBX-2120

Adds 1.2" (30.5mm) of Extension For 2" Focusers and Accessories Non-Marring Brass Clamp Ring Dual Thumbscrews for Secure Lock Accepts Standard 2" ...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue 2.4" Accessory Tube - 0.040" (1mm) 2
Tele Vue 2.4" Accessory Tube - 0.040" (1mm) 1
$23.00 - $23.00
$23.00
$23.00 - $23.00
$23.00

Tele Vue 2.4" Accessory Tube - 0.040" (1mm)

TV-TLF-0040

Extension Provided: 1mm (0.040") Accessory Standard: Tele Vue 2.4" Imaging System Connection Type: Threaded Material: Black Anodized Aluminum Oute...

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$23.00 - $23.00
$23.00
$23.00 - $23.00
$23.00
Tele Vue 2.4" Accessory Tube - 0.080" (2mm) 2
Tele Vue 2.4" Accessory Tube - 0.080" (2mm) 1
$23.00 - $23.00
$23.00
$23.00 - $23.00
$23.00

Tele Vue 2.4" Accessory Tube - 0.080" (2mm)

TV-TLG-0080

Extension Length: 2mm (0.080") Connection Type: Tele Vue 2.4" Proprietary Thread Format: Accessory Tube Material: Black Anodized Aluminum Compatib...

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$23.00 - $23.00
$23.00
$23.00 - $23.00
$23.00
Tele Vue 2.4" Accessory Tube - 0.25" (6.4mm) 2
Tele Vue 2.4" Accessory Tube - 0.25" (6.4mm) 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue 2.4" Accessory Tube - 0.25" (6.4mm)

TV-TLA-0250

Component Type: Fixed Extension Tube System Format: Tele Vue 2.4" Imaging System Optical Length: 0.25" (6.4mm) Connection Side 1: M61x1 Male Threa...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue 2.4" Accessory Tube - 0.375" (9.5mm) 2
Tele Vue 2.4" Accessory Tube - 0.375" (9.5mm) 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue 2.4" Accessory Tube - 0.375" (9.5mm)

TV-TLB-0375

Extension Length: 9.5mm (0.375") Format: Tele Vue 2.4" Accessory Standard Connection Side 1: 2.4" Female Thread Connection Side 2: 2.4" Male Threa...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue 2.4" Accessory Tube - 0.50" (12.7mm) 2
Tele Vue 2.4" Accessory Tube - 0.50" (12.7mm) 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue 2.4" Accessory Tube - 0.50" (12.7mm)

TV-TLC-0500

Extension Length: 0.50" (12.7mm) Connection Standard: Tele Vue 2.4" Imaging System Thread Material: Black Anodized Aluminum Clear Aperture: >2....

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue 2.4" Accessory Tube - 1.0 (25.4mm) 2
Tele Vue 2.4" Accessory Tube - 1.0 (25.4mm) 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue 2.4" Accessory Tube - 1.0 (25.4mm)

TV-TLD-1000

Extension Length: 1.0" (25.4mm) Format: Tele Vue 2.4" Imaging System Connection Side 1: 2.4" Male Thread Connection Side 2: 2.4" Female Thread Mat...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue 2.4" Adapter for 2" Accessories 2
Tele Vue 2.4" Adapter for 2" Accessories 1
$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00

Tele Vue 2.4" Adapter for 2" Accessories

TV-A2A-1107

Connection Side 1: 2.4" Female Thread for Tele Vue NPis Focusers Connection Side 2: 2" Accessory Barrel with Brass Clamp Ring Material: Anodized A...

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$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00
Tele Vue 48-mm Filter Adapter for 2.4" 2
Tele Vue 48-mm Filter Adapter for 2.4" 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue 48mm Filter Adapter for 2.4"

TV-AFT-1105

Connection (Telescope Side): Tele Vue 2.4" Female Thread Connection (Filter Side): M48x0.75 Male Thread (Standard 2" Filter Thread) Application: T...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue Canon Wide T Adapter w-Bayonet for 2.4" 1
$69.00 - $69.00
$69.00
$69.00 - $69.00
$69.00

Tele Vue Canon Wide T Adapter w-Bayonet for 2.4"

TV-CWT-2070

Connections: Canon EOS Bayonet (Camera Side) / Tele Vue 2.4" Thread (Telescope Side) Clear Aperture: 25% larger than standard T-rings Application:...

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$69.00 - $69.00
$69.00
$69.00 - $69.00
$69.00
Tele Vue Equalizer HiHat Adapter - 2" - 1.25" 1
$88.00 - $88.00
$88.00
$88.00 - $88.00
$88.00

Tele Vue Equalizer HiHat Adapter - 2" - 1.25"

TV-BEC-0005

Function: Balances telescope when switching between 2" and 1.25" eyepieces Compatibility: 2" focusers and diagonals Eyepiece Size: Accepts 1.25" e...

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$88.00 - $88.00
$88.00
$88.00 - $88.00
$88.00
Tele Vue Flat top Adapter - 2" - 1.25" 1
$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00

Tele Vue Flat top Adapter - 2" - 1.25"

TV-ACF-2125

Adapter Type: 2" to 1.25" Reducer Profile: Flat Top (Low Profile) Locking Mechanism: Brass Clamp Ring Compatibility: 2" Focusers and Diagonals Eye...

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$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00
Tele Vue Imaging System Nosepiece for Focuser - 2" 1
$69.00 - $69.00
$69.00
$69.00 - $69.00
$69.00

Tele Vue Imaging System Nosepiece for Focuser - 2"

TV-RAD-1074

Connection to Telescope: 2" Barrel Connection to Camera Side: Tele Vue Imaging System Thread Filter Compatibility: Standard 2" (48mm) Filter Threa...

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$69.00 - $69.00
$69.00
$69.00 - $69.00
$69.00
Tele Vue In-Travel Adapter - 2" - 1.25" 2
Tele Vue In-Travel Adapter - 2" - 1.25" 1
$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00

Tele Vue In-Travel Adapter - 2" - 1.25"

TV-AIT-2125

Function: Reduces focuser in-travel requirements Compatibility: 2" focusers and diagonals Accessory Size: 1.25" eyepieces and accessories Locking ...

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$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00
Tele Vue M54 Camera Adapter for 2.4" 2
Tele Vue M54 Camera Adapter for 2.4" 1
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Tele Vue M54 Camera Adapter for 2.4"

TV-M54-1073

Telescope Connection: Tele Vue 2.4" Imaging System Thread Camera Connection: M54x0.75 Male Thread Material: Black Anodized Aluminum Compatibility:...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Tele Vue Nikon F Wide T Adapter w-Bayonet for 2.4" 2
Tele Vue Nikon F Wide T Adapter w-Bayonet for 2.4" 1
$69.00 - $69.00
$69.00
$69.00 - $69.00
$69.00

Tele Vue Nikon F Wide T Adapter w-Bayonet for 2.4"

TV-NWT-2073

Connection to Telescope: Tele Vue 2.4" Imaging System Thread Connection to Camera: Nikon F-mount Bayonet Clear Aperture: >42mm (Wider than stan...

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$69.00 - $69.00
$69.00
$69.00 - $69.00
$69.00

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.