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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.

Filters

CA$830.00 - CA$830.00
CA$830.00
CA$830.00 - CA$830.00
CA$830.00

APM 3.7" ZTA Deluxe Focuser

APM-37-Deluxe
Only 1 left!

APM 3.7" Rack and Pinion Deluxe FocuserThe new 3,7" focuser is a Rack and Pinion type, with 1:10 focusing. It remains rigid under high loads making...

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CA$830.00 - CA$830.00
CA$830.00
CA$830.00 - CA$830.00
CA$830.00
Askar 50P AF KIT
CA$111.00 - CA$111.00
CA$111.00
CA$111.00 - CA$111.00
CA$111.00

Askar 50P AF KIT

ASK-50P-AFKIT
5 in stock

Enables automated focusing for the Askar 50P astrograph Compatible with almost all brands of electronic focusers Eliminates manual focus adjustmen...

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CA$111.00 - CA$111.00
CA$111.00
CA$111.00 - CA$111.00
CA$111.00
Askar ACL200 AF Kit
CA$151.00 - CA$151.00
CA$151.00
CA$151.00 - CA$151.00
CA$151.00

Askar ACL200 AF Kit

ASK-ASKAREAFKIT
1 in stock

Adds electronic autofocus capability to the Askar ACL200 lens Designed for seamless integration with ZWO EAF and other electronic focusers Include...

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CA$151.00 - CA$151.00
CA$151.00
CA$151.00 - CA$151.00
CA$151.00
CA$119.00 - CA$119.00
CA$119.00
CA$119.00 - CA$119.00
CA$119.00

Askar AF Kit for FMA180 Pro

ASK-ASKAF180P
1 in stock

Enables Electronic Autofocus on the Askar FMA180 Pro Designed for Seamless Integration with ZWO EAF Broadly Compatible with Most Electronic Focuse...

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CA$119.00 - CA$119.00
CA$119.00
CA$119.00 - CA$119.00
CA$119.00
Askar FRA400C AF Kit
CA$41.00 - CA$41.00
CA$41.00
CA$41.00 - CA$41.00
CA$41.00

Askar FRA400C AF Kit

ASK-FRA400C-AFKIT

Enables Automatic Focusing on the Askar FRA400C Compatible with Most Brands of Electronic Focusers Includes Five Synchronous Belts for a Secure Fi...

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CA$41.00 - CA$41.00
CA$41.00
CA$41.00 - CA$41.00
CA$41.00
CA$55.00 - CA$55.00
CA$55.00
CA$55.00 - CA$55.00
CA$55.00

Askar Multi-Connection Finder Plate 150

ASK-MCP150
2 in stock

Designed specifically for the Askar FRA600/5.6 Astrograph Provides a standard Vixen-style dovetail connection point Compatible with various Askar ...

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CA$55.00 - CA$55.00
CA$55.00
CA$55.00 - CA$55.00
CA$55.00
CA$48.00 - CA$48.00
CA$48.00
CA$48.00 - CA$48.00
CA$48.00

Askar Multi-Connection Finder Plate 90

ASK-ASKARMCP90
1 in stock

Designed for a seamless fit with the Askar FRA400/5.6 Astrograph Accepts any accessory with a standard Vixen-style dovetail foot Provides a secure...

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CA$48.00 - CA$48.00
CA$48.00
CA$48.00 - CA$48.00
CA$48.00
CA$122.00 - CA$122.00
CA$122.00
CA$122.00 - CA$122.00
CA$122.00

Askar SQA55 Autofocus Kit

ASK-SQA55AFKIT

Designed specifically for the Askar SQA55 Astrograph Enables autofocus with nearly all brands of electronic focusers Includes 4 MXL belts and 2 pu...

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CA$122.00 - CA$122.00
CA$122.00
CA$122.00 - CA$122.00
CA$122.00
Askar Worm-and-Gear Automatic Telescope Focuser (WAF)
CA$279.00 - CA$279.00
CA$279.00
CA$279.00 - CA$279.00
CA$279.00

Askar Worm-and-Gear Automatic Telescope Focuser (WAF)

ASK-ASKARWAF

20 kg Equivalent Load Capacity 0.0182° Minimum Resolution Step Size 1:99 Worm-Gear Stepper Motor Native ASCOM Alpaca & Indigo Support 373 g Bo...

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CA$279.00 - CA$279.00
CA$279.00
CA$279.00 - CA$279.00
CA$279.00
CA$46.00 - CA$46.00
CA$46.00
CA$46.00 - CA$46.00
CA$46.00

Baader Ultrashort Clamp - 1.25"/T-2

BAA-2458121

Connects 1.25" accessories to T-2 threads Ultrashort design minimizes optical path length Ideal for complex imaging trains with limited back focus...

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CA$46.00 - CA$46.00
CA$46.00
CA$46.00 - CA$46.00
CA$46.00
CA$132.00 - CA$132.00
CA$132.00
CA$132.00 - CA$132.00
CA$132.00

Baader Ultrashort Eyepiece Clamp - 2"/M68x1(M)/M60x0.75(M)

BAA-2458196

Securely holds 2" eyepieces and accessories Ultra-low profile design minimizes backfocus consumption Features male M68x1 Zeiss-system threads on b...

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CA$132.00 - CA$132.00
CA$132.00
CA$132.00 - CA$132.00
CA$132.00
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

Baader 2" Four-in-One Clamp Adapter M68 (Zeiss)/2.7" (A.P.)/M60 (Vixen)/M56 (Synta)

BAA-2458190
1 in stock

Adapts four major large-format focusers to a 2" clamp Female threads: M68 (Zeiss), 2.7" (Astro-Physics) Female threads: M60 (Vixen), M56 (Synta/Sk...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00

Baader 2" Locking Ring for SCTs 8"/9.25"/11"/14"

BAA-2458270
1 in stock

Direct-threads to the rear cell of Schmidt-Cassegrain telescopes Compatible with 8", 9.25", 11", and 14" SCT models Designed for Baader 2" zenith ...

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CA$70.00 - CA$70.00
CA$70.00
CA$70.00 - CA$70.00
CA$70.00
CA$59.00 - CA$59.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00

Baader Adapter - 1.25"/0.965"

BAA-2408191

Adapts 1.25" (1¼") focusers to accept 0.965" (24.5mm) eyepieces Brings classic and vintage eyepieces into use with modern telescopes Precision-mac...

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CA$59.00 - CA$59.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00
CA$67.00 - CA$67.00
CA$67.00
CA$67.00 - CA$67.00
CA$67.00

Baader Adapter - 1.25"/2"" w/ T-2 Thread

BAA-2408190

Reduces a 2" focuser to accept 1.25" accessories Features an external male T-2 thread for direct camera attachment Non-marring brass compression r...

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CA$67.00 - CA$67.00
CA$67.00
CA$67.00 - CA$67.00
CA$67.00
CA$79.00 - CA$79.00
CA$79.00
CA$79.00 - CA$79.00
CA$79.00

Baader Adapter - 2" NexStar 4 (C90)/ETX

BAA-2958500

Connects Celestron C90/NexStar 4 and Meade ETX telescopes to 2" accessories Enables the use of 2" diagonals for wider true fields of view Accepts ...

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CA$79.00 - CA$79.00
CA$79.00
CA$79.00 - CA$79.00
CA$79.00
CA$43.00 - CA$43.00
CA$43.00
CA$43.00 - CA$43.00
CA$43.00

Baader Adapter Diamond Steeltrack - M48x0.75(M)

BAA-2957204

Connects M48x0.75 Accessories to Baader Diamond Steeltrack Focusers Male M48x0.75 Output Thread Provides a Secure, Threaded Connection for Imaging...

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CA$43.00 - CA$43.00
CA$43.00
CA$43.00 - CA$43.00
CA$43.00
CA$40.00 - CA$40.00
CA$40.00
CA$40.00 - CA$40.00
CA$40.00

Baader Adapter Diamond Steeltrack - T-2(M)

BAA-2957202

Connects T-2 (M42x0.75) accessories to Baader Diamond Steeltrack focusers Provides a secure, rigid, all-threaded connection Male T-2 thread output...

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CA$40.00 - CA$40.00
CA$40.00
CA$40.00 - CA$40.00
CA$40.00
CA$57.00 - CA$57.00
CA$57.00
CA$57.00 - CA$57.00
CA$57.00

Baader Adapter Diamond Steeltrack Adapter -M68x0.75(M)

BAA-2957206

Adapts Baader Diamond Steeltrack focusers Provides a male M68x0.75 thread Ensures a rigid, non-flexing connection for imaging Machined for a preci...

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CA$57.00 - CA$57.00
CA$57.00
CA$57.00 - CA$57.00
CA$57.00
CA$40.00 - CA$40.00
CA$40.00
CA$40.00 - CA$40.00
CA$40.00

Baader Adapter NT Steeltrack - 2"/1.25"

BAA-2408152

Reduces 2" focusers to accept 1.25" eyepieces and accessories Adds only 4.5mm of optical height, preserving critical back focus Engineered specifi...

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CA$40.00 - CA$40.00
CA$40.00
CA$40.00 - CA$40.00
CA$40.00
CA$30.00 - CA$30.00
CA$30.00
CA$30.00 - CA$30.00
CA$30.00

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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CA$30.00 - CA$30.00
CA$30.00
CA$30.00 - CA$30.00
CA$30.00
CA$121.00 - CA$121.00
CA$121.00
CA$121.00 - CA$121.00
CA$121.00

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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CA$121.00 - CA$121.00
CA$121.00
CA$121.00 - CA$121.00
CA$121.00
CA$127.00 - CA$127.00
CA$127.00
CA$127.00 - CA$127.00
CA$127.00

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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CA$127.00 - CA$127.00
CA$127.00
CA$127.00 - CA$127.00
CA$127.00
CA$116.00 - CA$271.00
CA$116.00 - CA$271.00
CA$116.00 - CA$271.00
CA$116.00

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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CA$116.00 - CA$271.00
CA$116.00 - CA$271.00
CA$116.00 - CA$271.00
CA$116.00

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.