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Focusers and Accessories

Focus is the difference between a sharp image and a nearly sharp one, and holding it across a Canadian night — where temperatures can drop fifteen degrees between dusk and dawn — is a mechanical problem, not a patience problem. David Astro carries focusers and focuser accessories in Canada, from Crayford and rack-and-pinion drawtubes to motor kits, rotators, compression rings and adapter flanges, in Canadian stock.

We fit focusers to telescopes routinely, including retrofits that require a specific flange or drawtube adapter. If you are replacing a stock focuser or adding motorization, tell us the telescope and we will confirm the fit.

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Baader Planetarium Adapter S58-short to M54a – for all BDS Diamond Steeltrack®
CA$51.00 - CA$51.00
CA$51.00
CA$51.00 - CA$51.00
CA$51.00

Baader Planetarium Adapter S58-short to M54a – for all BDS Diamond Steeltrack®

BAA-2957209

Adapts the Baader S58 drawtube thread to a female M54a thread Designed for all Baader Diamond Steeltrack® (BDS) focusers Enables direct connection...

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CA$51.00 - CA$51.00
CA$51.00
CA$51.00 - CA$51.00
CA$51.00
Baader Planetarium Adapter S58-short to M68i – for all BDS Diamond Steeltrack®
CA$79.00 - CA$79.00
CA$79.00
CA$79.00 - CA$79.00
CA$79.00

Baader Planetarium Adapter S58-short to M68i – for all BDS Diamond Steeltrack®

BAA-2957207

Adapts the Baader S58 dovetail thread to M68i Provides a secure, rigid M68i female (internal) thread connection Designed for all Baader Diamond St...

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CA$79.00 - CA$79.00
CA$79.00
CA$79.00 - CA$79.00
CA$79.00
Baader Planetarium BDS-SC Adapter S88i to M48i
CA$158.00 - CA$158.00
CA$158.00
CA$158.00 - CA$158.00
CA$158.00

Baader Planetarium BDS-SC Adapter S88i to M48i

BAA-2957297

Connects Baader Diamond Steeltrack SC (BDS-SC) focusers to M48 accessories Provides a standard female M48 (M48x0.75) accessory thread Enables a ri...

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CA$158.00 - CA$158.00
CA$158.00
CA$158.00 - CA$158.00
CA$158.00
Baader Planetarium Mark IV Zoom Adapter to M45 – for Zeiss-Diascope
CA$75.00 - CA$75.00
CA$75.00
CA$75.00 - CA$75.00
CA$75.00

Baader Planetarium Mark IV Zoom Adapter to M45 – for Zeiss-Diascope

BAA-2454831

Adapts Baader Hyperion Mark IV Zoom eyepiece to Zeiss Diascopes Provides a secure M45x0.5 threaded connection Ensures perfect optical alignment Re...

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CA$75.00 - CA$75.00
CA$75.00
CA$75.00 - CA$75.00
CA$75.00
Baader Planetarium Sky Surfer III – Adapter for large telescopes made of ABS
CA$11.00 - CA$11.00
CA$11.00
CA$11.00 - CA$11.00
CA$11.00

Baader Planetarium Sky Surfer III – Adapter for large telescopes made of ABS

BAA-2957304

Securely mounts the Baader Sky Surfer III finder Designed for use on large telescope optical tubes Constructed from durable, lightweight ABS plast...

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CA$11.00 - CA$11.00
CA$11.00
CA$11.00 - CA$11.00
CA$11.00
Baader Planetarium Sky Surfer III – Flat base adapter made of ABS
CA$10.00 - CA$10.00
CA$10.00
CA$10.00 - CA$10.00
CA$10.00

Baader Planetarium Sky Surfer III – Flat base adapter made of ABS

BAA-2957302

Adapts Sky Surfer III for flat-surface mounting Enables use on square tube telescopes and mounting rings Constructed from durable, lightweight ABS...

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CA$10.00 - CA$10.00
CA$10.00
CA$10.00 - CA$10.00
CA$10.00
Baader Planetarium Steeldrive II Adapter set for FeatherTouch 3.5" focusers
CA$168.00 - CA$168.00
CA$168.00
CA$168.00 - CA$168.00
CA$168.00

Baader Planetarium Steeldrive II Adapter set for FeatherTouch 3.5" focusers

BAA-2957270

Enables motorization of FeatherTouch 3.5" focusers Designed for the Baader Steeldrive II motor Provides a secure, no-slip mechanical coupling Faci...

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CA$168.00 - CA$168.00
CA$168.00
CA$168.00 - CA$168.00
CA$168.00
Baader Planetarium Steeldrive II Belt Cover – 3D-printed
CA$75.00 - CA$75.00
CA$75.00
CA$75.00 - CA$75.00
CA$75.00

Baader Planetarium Steeldrive II Belt Cover – 3D-printed

BAA-2957259

Protects Steeldrive II belt and pulleys Shields drive system from dew, dust, and debris Prevents accidental snags on cables or clothing Custom-des...

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CA$75.00 - CA$75.00
CA$75.00
CA$75.00 - CA$75.00
CA$75.00
Baader Planetarium Baader Steeldrive II Controller
CA$648.00 - CA$648.00
CA$648.00
CA$648.00 - CA$648.00
CA$648.00

Baader Planetarium Steeldrive II Controller

BAA-2957260

Standalone hand controller for Baader Steeldrive II motor units Three distinct, selectable focusing modes for any scenario Full computer control a...

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CA$648.00 - CA$648.00
CA$648.00
CA$648.00 - CA$648.00
CA$648.00
Baader Planetarium Baader Steeldrive II Motor Unit
CA$401.00 - CA$401.00
CA$401.00
CA$401.00 - CA$401.00
CA$401.00

Baader Planetarium Steeldrive II Motor Unit

BAA-2957265

High-torque stepper motor handles heavy imaging loads Timing belt drive eliminates backlash for precise autofocus Contactless homing sensor enable...

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CA$401.00 - CA$401.00
CA$401.00
CA$401.00 - CA$401.00
CA$401.00
Baader Planetarium Universal Red Dot Mount RDM
CA$54.00 - CA$54.00
CA$54.00
CA$54.00 - CA$54.00
CA$54.00

Baader Planetarium Universal Red Dot Mount RDM

BAA-2457010

Adapts 11mm Weaver-rail finders to standard Vixen/Synta-style finder shoes 70mm riser height for comfortable head positioning Durable all-metal co...

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CA$54.00 - CA$54.00
CA$54.00
CA$54.00 - CA$54.00
CA$54.00
CA$76.00 - CA$76.00
CA$76.00
CA$76.00 - CA$76.00
CA$76.00

Baader Pushfix Low Profile Adapter - 1.25"/2" for Steeltrack NT Focusers

BAA-2408151

Reduces 2" focusers to accept 1.25" accessories Designed specifically for Baader Steeltrack NT focusers Pushfix quick-release mechanism with adjus...

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CA$76.00 - CA$76.00
CA$76.00
CA$76.00 - CA$76.00
CA$76.00
CA$81.00 - CA$81.00
CA$81.00
CA$81.00 - CA$81.00
CA$81.00

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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CA$81.00 - CA$81.00
CA$81.00
CA$81.00 - CA$81.00
CA$81.00
CA$303.00 - CA$303.00
CA$303.00
CA$303.00 - CA$303.00
CA$303.00

Baader RT-Adapter Diamond Steeltrack - 4.2" Explore Scientific

BAA-2957285

Connects Baader Diamond Steeltrack focusers to Explore Scientific refractors Designed specifically for tubes with a 4.2" outer diameter Enables a ...

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CA$303.00 - CA$303.00
CA$303.00
CA$303.00 - CA$303.00
CA$303.00
CA$158.00 - CA$158.00
CA$158.00
CA$158.00 - CA$158.00
CA$158.00

Baader RT-Adapter Diamond Steeltrack - Intes Micro D66

BAA-2957296

Connects Baader BDS-RT Focuser to Intes Micro Telescopes Designed for the D66 Mounting Flange Provides a Rigid, Secure Mechanical Connection Maint...

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CA$158.00 - CA$158.00
CA$158.00
CA$158.00 - CA$158.00
CA$158.00
CA$172.00 - CA$172.00
CA$172.00
CA$172.00 - CA$172.00
CA$172.00

Baader RT-Adapter Diamond Steeltrack for Refractors - M93x1(F)

BAA-2957281

Adapts Baader Diamond Steeltrack Focusers to Refractors Features a Female M93x1 Thread Connects to Telescope Tubes with a Male M93x1 Thread Provid...

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CA$172.00 - CA$172.00
CA$172.00
CA$172.00 - CA$172.00
CA$172.00
CA$57.00 - CA$57.00
CA$57.00
CA$57.00 - CA$57.00
CA$57.00

Baader RT-Adapter Diamond Steeltrack for Sky-Watcher Refractors - M90x1(F)

BAA-2957283

Adapts Baader Diamond Steeltrack Focusers Fits Sky-Watcher Refractors Connects to M90x1 Female Threads Enables Precision Focuser Upgrades Descr...

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CA$57.00 - CA$57.00
CA$57.00
CA$57.00 - CA$57.00
CA$57.00
CA$59.00 - CA$59.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00

Baader RT-Adapter Diamond Steeltrack for Sky-Watcher Refractors - M90x1.5(M)

BAA-2957284

Adapts Baader Diamond Steeltrack focusers to select Sky-Watcher refractors Connects to the telescope's M90x1.5 male rear thread Enables a high-pre...

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CA$59.00 - CA$59.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00
CA$63.00 - CA$63.00
CA$63.00
CA$63.00 - CA$63.00
CA$63.00

Baader RT-Adapter Diamond Steeltrack for Synta/Celestron Refractors - Ø97mm

BAA-2957282

Adapter for Baader Diamond Steeltrack Focuser For Select Synta and Celestron Refractors Enables High-Precision Focuser Upgrade Requires Specific I...

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CA$63.00 - CA$63.00
CA$63.00
CA$63.00 - CA$63.00
CA$63.00
CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00

Baader RT-Adapter Diamond Steeltrack for Vixen Refractors - M88x1(F)

BAA-2957280

Adapts Baader Diamond Steeltrack focusers to Vixen refractors Female M88x1 thread for direct connection Enables focuser upgrades for astrophotogra...

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CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00
CA$222.00 - CA$222.00
CA$222.00
CA$222.00 - CA$222.00
CA$222.00

Baader SC-Adapter Diamond Steeltrack - 4" Meade

BAA-2957295

Connects Baader Diamond Steeltrack Focusers to select Meade Refractors Designed for telescopes with a 4" female internal thread Precision-machined...

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CA$222.00 - CA$222.00
CA$222.00
CA$222.00 - CA$222.00
CA$222.00
CA$13.00 - CA$13.00
CA$13.00
CA$13.00 - CA$13.00
CA$13.00

Baader Sky Surfer III Adapter for Binoculars

BAA-2957305
1 in stock

Adapts Baader Sky Surfer III to Binoculars Mounts to Standard 1/4"-20 Tripod Sockets Enables Intuitive "Both-Eyes-Open" Targeting Ideal for High-M...

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CA$13.00 - CA$13.00
CA$13.00
CA$13.00 - CA$13.00
CA$13.00
CA$12.00 - CA$12.00
CA$12.00
CA$12.00 - CA$12.00
CA$12.00

Baader Sky Surfer III Adapter for Spotting Scopes

BAA-2957306

Adapts Baader Sky Surfer III to Spotting Scopes Enables Fast, Intuitive Target Acquisition Ideal for Terrestrial and Astronomical Use ...

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CA$12.00 - CA$12.00
CA$12.00
CA$12.00 - CA$12.00
CA$12.00
CA$66.00 - CA$66.00
CA$66.00
CA$66.00 - CA$66.00
CA$66.00

Baader Sky Surfer III 30mm Red Dot Finder

BAA-2957300
2 in stock

Zero-Magnification Red Dot Finder High-Transmission Anti-Reflection Coatings Dual-Use Housing for Solar Alignment Universal Mounting System Compat...

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CA$66.00 - CA$66.00
CA$66.00
CA$66.00 - CA$66.00
CA$66.00

Focuser Mechanics and What Matters Under Load

A focuser has to hold a camera train weighing several kilograms perfectly square to the optical axis while moving in increments of a few microns. Two things determine whether it does: the drive mechanism and the load rating.

  • Crayford focusers: A friction roller on a flat surface, giving smooth, backlash-free travel. Excellent for visual and light imaging loads; can slip under heavy trains, particularly when pointed near zenith.
  • Rack-and-pinion focusers: Toothed engagement that will not slip regardless of load, which is why most heavy imaging trains use them. Modern designs have effectively eliminated the old backlash complaints.
  • Motorized and electronic focusers: Stepper-driven focus with position repeatability, enabling autofocus routines and temperature compensation across a session.
  • Rotators: Precise framing and camera angle control without breaking the imaging train, and essential for optimizing off-axis guide star placement.
  • Compression rings: Replace a single set screw that tilts and marks your barrel with even radial clamping — a small part with a visible effect on star shapes.
  • Adapters and flanges: Telescope-specific mounting plates that let a third-party focuser replace a stock one.

Why Choose David Astro for Focusers and Accessories

Focuser upgrades are one of the most cost-effective improvements in astrophotography, and one of the easiest to order incorrectly.

  • Retrofit fit checks: We identify the adapter flange your specific telescope needs, and confirm that the new focuser's travel and profile will still let you reach focus.
  • Load rating advice: We weigh your intended imaging train against the focuser's rated capacity, including the tilt load that shows up when the tube is near zenith.
  • Authorized dealer: Genuine parts with full manufacturer warranty, serviced in Canada.
  • Canadian stock: In-stock focusers and accessories ship domestically without duties or brokerage charges.
  • In-house repair: We service focuser mechanics and electronics directly, which matters for a component with moving parts that see heavy use.

Focusers in Canada — Frequently Asked Questions

Crayford or rack-and-pinion for imaging?
Rack-and-pinion, once your imaging train exceeds roughly 2 kg. A Crayford's friction drive can slip under load at steep angles, and the slip is often mistaken for focus drift.
Will a motorized focuser fit my existing focuser?
Often yes, through a telescope-specific bracket that couples to the fine-focus shaft. Tell us the focuser model and we will confirm whether a bracket exists or a full replacement is needed.
How much does focus shift with temperature?
Enough to matter. A metal tube contracts measurably over a 15 degree drop, and at fast focal ratios the critical focus zone is only tens of microns. Temperature-compensated autofocus solves it.
Do you carry focusers for older telescopes?
We carry a wide range of adapter flanges covering many discontinued tubes. Send us the make and drawtube diameter and we will check.

Upgrading your focuser?

Tell us your telescope and imaging train weight and we will specify the right focuser and flange. Canadian stock, expert fitting advice.