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.
Filters
Baader M68 Extension Tube - 20mm
Adds a fixed 20mm of back focus Features large M68 x 1 threads for rigid, no-flex connections Integral part of the Baader M68 Tele-Compendium syst...
View full detailsBaader M68 Extension Tube - 40mm
40mm Fixed Extension Length M68 x 1mm Male and Female Threads Provides Rigid, Flexure-Free Spacing Component of the Baader M68 Tele-Compendium Sys...
View full detailsBaader M68 Extension Tube - 60mm
Adds a fixed length of spacing to M68 systems M68 female and male threads for a secure, non-flexing connection Matte black interior surfaces reduc...
View full detailsBaader M68 Extension Tube - 7.5mm
Provides 7.5mm of fixed extension M68 x 1mm female and male threads Maintains a large, unvignetted clear aperture Precision machined for accurate ...
View full detailsBaader M68 Extension Tube - 80mm
Adds 80mm of fixed extension M68 x 1mm threads on both ends Prevents optical train flexure and tilt Precision-machined for rigid connections Matte...
View full detailsBaader M68 Fine-Adjustment Aluminum Ring - 0.3/0.5/1mm
Precisely adjusts M68 back focus Available in 0.3mm, 0.5mm, and 1mm thicknesses Enables fine rotational adjustment of cameras and accessories Thin...
View full detailsBaader M68 Tele-Compendium
Establishes a rigid, non-flexing M68 threaded connection Functions as a variable-length stray light shield (compendium) Adapts T-2 thread accessor...
View full detailsBaader Morpheus Adapter - M43/M54
Adapts Morpheus M43 thread to M54 Enables direct connection of Baader HDT-Rings Creates a rigid, non-flexing imaging train Designed for afocal pho...
View full detailsBaader Nosepiece - 1.25" /T-2
Adapts T-2 (M42x0.75) Threads to a 1.25" Barrel Integrates with the Baader Astro T-2 System Standard 1.25" Nosepiece Format Enables Connection of ...
View full detailsBaader Nosepiece - 2"/2" SCT(M) Thread
2" ultra hard nose piece with safety groove Focus side 50.8mm male thread (SCT thread) Telescope side 2" with 48mm filter thread Can be used for n...
View full detailsBaader Nosepiece - 2"/S52
Adapts Baader S52 accessories to a standard 2" focuser Integrated safety groove prevents slippage and protects equipment Features Baader's S52 dov...
View full detailsBaader Nosepiece - 2"/T-2
Connects 2" focusers to T-2 (M42x0.75) accessories Features a secondary M48 male thread for 2" filters Ultra low-profile design minimizes back foc...
View full detailsBaader Nosepiece Extension - 1.25"
Adds 18mm of extension length Standard 1.25" outer diameter Threads into 1.25" eyepiece filter threads Features male and female 1.25" filter threa...
View full detailsBaader Nosepiece w/ Safety Kerf - 2"
2" Barrel Diameter Connects to Male 2" SC-Thread Baader Safety Kerf Anti-Slip Grooves Ultra-Hard Anodized Finish Replaces Standard Undercut Design...
View full detailsBaader Pentax Adapter M84/M68 (Zeiss)
Adapts Pentax M84 female threads to the Baader M68 male thread system Creates a rigid, non-flexing connection for heavy imaging payloads Eliminate...
View full detailsBaader Planetarium 1.25" Nosepiece to T-2a – with Safety-Kerf
Connects T-2 accessories to a 1.25" focuser or visual back Modern 3mm T-2 thread depth for cameras with short optical height Safety-Kerf groove pr...
View full details
Save 0%
Save %
Baader Planetarium 2" Deluxe Eyepiece Clamp for SC-telescopes – with 2" filter thread
Baader Planetarium 2" Deluxe Eyepiece Clamp for SC-telescopes – with 2" filter thread
Adapts Schmidt-Cassegrain telescopes to use 2-inch accessories Internal 2-inch filter thread for optical tube protection Securely holds heavy diag...
View full detailsBaader Planetarium 2" Deluxe Eyepiece Clamp for SC-telescopes – with 2" Nosepiece
Adds 60mm of optical length to the light path Securely clamps 2-inch eyepieces and accessories Integrated dual 2-inch filter holder Connects to st...
View full detailsBaader Planetarium 2" Nosepiece to M45a – for Hyperion® Zoom MK III
Converts the Hyperion® Zoom MK III eyepiece to a native 2" barrel Threads directly to the eyepiece's M45a body thread Eliminates the need for a se...
View full detailsBaader Planetarium 2" Nosepiece to M54a – with Safety-Kerf
Connects M54 threaded accessories to any 2" focuser or adapter M54 external (male) thread provides a wide, secure connection Features Baader's Saf...
View full detailsBaader Planetarium 3.5" Quick Changer and Instrument Rotator for PlaneWave
Enables secure, rotation-proof mounting of heavy accessories Designed for the 3.5" Hedrick Focuser on PlaneWave CDK 14" to 24" telescopes Allows f...
View full detailsBaader Planetarium 3.5" Quick Changer Ring
Enables rapid exchange of heavy instrument packages Designed for the 3.5" Hedrick Focuser Compatible with PlaneWave CDK 14" to 24" telescopes Allo...
View full detailsBaader Planetarium Adapter 1"a C-Mount to T-2i – incl. UV/IR Cut Filter
Adapts C-Mount (1" x 32 TPI) threads to the T-2 (M42x0.75) system Integrates a factory-mounted UV/IR Cut Filter Provides a critical link for guide...
View full detailsBaader Planetarium Adapter 3"i to M68a – for FLI / SBIG
Connects devices with a 3" internal thread to an M68 external thread Designed specifically for FLI filter wheels and SBIG STX series cameras Enabl...
View full detailsUnderstanding 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.