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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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PrimaLuceLab 3" Visual Back for ESATTO 3.5” LP
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

PrimaLuceLab 3" Visual Back for ESATTO 3.5” LP

PLL-PL8410011

Adapts ESATTO 3.5" LP focusers to accept 3" accessories Internal brass compression ring prevents scratches Multiple locking screws ensure a secure...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
CA$106.00 - CA$106.00
CA$106.00
CA$106.00 - CA$106.00
CA$106.00

PrimaLuceLab 33mm Adapter for SESTO SENSO 2

PLL-SESTOSENSO-AD33II

This 33mm adapter allows you to install SESTO SENSO 2 on focusers that come with a 33mm diameter shaft, like 2,5" and 3" FeatherTouch focusers (or ...

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CA$106.00 - CA$106.00
CA$106.00
CA$106.00 - CA$106.00
CA$106.00
CA$119.00 - CA$119.00
CA$119.00
CA$119.00 - CA$119.00
CA$119.00

PrimaLuceLab 37mm Adapter for SESTO SENSO 2

PLL-SESTOSENSO-AD37II

Adapts SESTO SENSO 2 for 37mm diameter focuser shafts Precision-made for focusers like the 3.5" FeatherTouch and Takahashi FSQ-130 Replaces the 2 ...

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CA$119.00 - CA$119.00
CA$119.00
CA$119.00 - CA$119.00
CA$119.00
PrimaLuceLab 40mm Extension Tube for ESATTO 3"
CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00

PrimaLuceLab 40mm Extension Tube for ESATTO 3"

PLL-PL3600317

Adds 40mm of back focus for ESATTO 3" focusers Enables focus with long-travel telescopes like refractors Precise dovetail coupling system for rigi...

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CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00

PrimaLuceLab 65mm Extension Tube for ESATTO 3"

PLL-PL3600284

Adds 65mm of extension for ESATTO 3" focusers Enables focus on telescopes with long-travel stock focusers Integrated dovetail coupling system for ...

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CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00
CA$69.00 - CA$69.00
CA$69.00
CA$69.00 - CA$69.00
CA$69.00

PrimaLuceLab Adapter ESATTO 2" for ARCO 2"

PLL-PL3600412

Connects the ARCO 2" Rotator directly to the ESATTO 2" Focuser Creates a combined rotator thickness of just 21mm Maintains a wide 51mm free apertu...

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CA$69.00 - CA$69.00
CA$69.00
CA$69.00 - CA$69.00
CA$69.00
CA$833.00 - CA$833.00
CA$833.00
CA$833.00 - CA$833.00
CA$833.00

PrimaLuceLab Adapter ESATTO 2" for Borg 55FL f3.6

PLL-PL3600248

Connects ESATTO 2" Focuser to Borg 55FL f/3.6 Telescope Creates a Secure, Direct-Threaded Connection Eliminates Potential for Tilt and Flexure in ...

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CA$833.00 - CA$833.00
CA$833.00
CA$833.00 - CA$833.00
CA$833.00
CA$111.00 - CA$111.00
CA$111.00
CA$111.00 - CA$111.00
CA$111.00

PrimaLuceLab Adapter ESATTO 2" for GSO/Orion/TPO Ritchey-Chretien 6 and 8"

PLL-PL3600235

Connects ESATTO 2" Robotic Focuser to select Ritchey-Chretien telescopes Compatible with GSO, Orion, and TPO 6" (152mm) and 8" (203mm) RC models E...

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CA$111.00 - CA$111.00
CA$111.00
CA$111.00 - CA$111.00
CA$111.00
CA$203.00 - CA$203.00
CA$203.00
CA$203.00 - CA$203.00
CA$203.00

PrimaLuceLab Adapter ESATTO 2" for Sky-Watcher/Orion ED80, ED100 and ED120

PLL-PL3600230

Connects ESATTO 2" Focuser to select refractors Compatible with Sky-Watcher/Orion ED80 Apochromatic Refractors Compatible with Sky-Watcher/Orion E...

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CA$203.00 - CA$203.00
CA$203.00
CA$203.00 - CA$203.00
CA$203.00
CA$231.00 - CA$231.00
CA$231.00
CA$231.00 - CA$231.00
CA$231.00

PrimaLuceLab Adapter ESATTO 2" for Sky-Watcher/Orion Newton 200 f4 and f5

PLL-PL3600229

Connects ESATTO 2" focusers to Sky-Watcher/Orion 200mm f/4 and f/5 Newtonians Maintains original focuser thickness to ensure prime focus is reacha...

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CA$231.00 - CA$231.00
CA$231.00
CA$231.00 - CA$231.00
CA$231.00
CA$231.00 - CA$231.00
CA$231.00
CA$231.00 - CA$231.00
CA$231.00

PrimaLuceLab Adapter ESATTO 2" for Sky-Watcher/Orion Newton 250 f4 and f5

PLL-PL3600237

Enables installation of the ESATTO 2" motorized focuser Designed specifically for Sky-Watcher/Orion Newton 250 f/4 and f/5 telescopes Maintains th...

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CA$231.00 - CA$231.00
CA$231.00
CA$231.00 - CA$231.00
CA$231.00
CA$203.00 - CA$203.00
CA$203.00
CA$203.00 - CA$203.00
CA$203.00

PrimaLuceLab Adapter ESATTO 2" for Takahashi FS-60Q

PLL-PL3600255

Connects PrimaLuceLab ESATTO 2" Focuser to Takahashi FS-60Q Telescopes Adds Only 5mm of Optical Thickness to the Imaging Train Enables High-Precis...

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CA$203.00 - CA$203.00
CA$203.00
CA$203.00 - CA$203.00
CA$203.00
CA$91.00 - CA$91.00
CA$91.00
CA$91.00 - CA$91.00
CA$91.00

PrimaLuceLab Adapter ESATTO 2" for Telescopes with Large 3.3" SC Thread

PLL-PL3600212

Connects ESATTO 2" focuser to large 3.3" SC threads Designed for Celestron 9.25", 11", and 14" SCT & EdgeHD telescopes Ultra-thin 2mm optical ...

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CA$91.00 - CA$91.00
CA$91.00
CA$91.00 - CA$91.00
CA$91.00
CA$49.00 - CA$49.00
CA$49.00
CA$49.00 - CA$49.00
CA$49.00

PrimaLuceLab Adapter ESATTO 2" for Telescopes with SC Thread

PLL-PL3600209

Connects ESATTO 2" Motorized Focuser to SC Telescope Threads Adds 0mm of Optical Thickness to the Imaging Train Compatible with Celestron SCT and ...

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CA$49.00 - CA$49.00
CA$49.00
CA$49.00 - CA$49.00
CA$49.00
PrimaLuceLab Adapter ESATTO 2" LP and ARCO 2" for telescopes with SC thread
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

PrimaLuceLab Adapter ESATTO 2" LP and ARCO 2" for telescopes with SC thread

PLL-PL3600542

Connects ESATTO 2" LP Focuser to SC threads Connects ARCO 2" Rotator to SC threads Enables a fully threaded, rigid imaging train Designed for Schm...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
PrimaLuceLab Adapter ESATTO 2" LP for ARCO 2"
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

PrimaLuceLab Adapter ESATTO 2" LP for ARCO 2"

PLL-PL3600538

Connects the PrimaLuceLab ESATTO 2" LP Focuser to the ARCO 2" Rotator Creates a rigid, unified imaging assembly with a 22mm combined thickness Mai...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
PrimaLuceLab Adapter ESATTO 2” LP for telescopes with large 3.3" SC thread
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

PrimaLuceLab Adapter ESATTO 2” LP for telescopes with large 3.3" SC thread

PLL-PL3600539

Connects ESATTO 2” LP to telescopes with a large 3.3" SC thread Designed for Celestron SCT (11" and 14") and EdgeHD (9.25", 11", and 14") models E...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
CA$97.00 - CA$97.00
CA$97.00
CA$97.00 - CA$97.00
CA$97.00

PrimaLuceLab Adapter ESATTO 3" for ARCO 2"

PLL-PL3600416

Connects ARCO 2" Rotator to ESATTO 3" Focuser Enables Direct Power and Control via ESATTO Port Creates a Rigid, Mechanically Coupled Imaging Train...

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CA$97.00 - CA$97.00
CA$97.00
CA$97.00 - CA$97.00
CA$97.00
CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00

PrimaLuceLab Adapter ESATTO 3" for ARCO 3"

PLL-PL3600458

Connects ESATTO 3" Focuser to ARCO 3" Rotator Enables Electronic Control via ESATTO Port Results in a Combined Rotator Thickness of 24.5mm Maintai...

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CA$133.00 - CA$133.00
CA$133.00
CA$133.00 - CA$133.00
CA$133.00
CA$273.00 - CA$273.00
CA$273.00
CA$273.00 - CA$273.00
CA$273.00

PrimaLuceLab Adapter ESATTO 3" for Borg 90FL and 107FL f3.9

PLL-PL3600268

Connects ESATTO 3" robotic focuser to Borg 90FL telescopes Connects ESATTO 3" robotic focuser to Borg 107FL f/3.9 telescopes Replaces the original...

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CA$273.00 - CA$273.00
CA$273.00
CA$273.00 - CA$273.00
CA$273.00
CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00

PrimaLuceLab Adapter ESATTO 3" for GSO/Orion/TPO Ritchey-Chretien 10, 12, 14 and 16"

PLL-PL3600236

Connects ESATTO 3" Focuser For 10", 12", 14", and 16" RC Telescopes Compatible with GSO, Orion, and TPO Models Provides a Rigid, Thread-On Connect...

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CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00
CA$413.00 - CA$413.00
CA$413.00
CA$413.00 - CA$413.00
CA$413.00

PrimaLuceLab Adapter ESATTO 3" for Meade 16" with 4" Thread

PLL-PL3600292

Connects ESATTO 3" focuser to Meade 16" telescopes Designed for the standard 4" rear cell thread Enables robotic focusing for heavy imaging payloa...

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CA$413.00 - CA$413.00
CA$413.00
CA$413.00 - CA$413.00
CA$413.00
CA$357.00 - CA$357.00
CA$357.00
CA$357.00 - CA$357.00
CA$357.00

PrimaLuceLab Adapter ESATTO 3" for Sky-Watcher ESPRIT 100 ED

PLL-PL3600288

Precision-engineered for the PrimaLuceLab ESATTO 3" robotic focuser Designed for a perfect fit on the Sky-Watcher ESPRIT 100 ED telescope Provides...

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CA$357.00 - CA$357.00
CA$357.00
CA$357.00 - CA$357.00
CA$357.00
CA$357.00 - CA$357.00
CA$357.00
CA$357.00 - CA$357.00
CA$357.00

PrimaLuceLab Adapter ESATTO 3" for Sky-Watcher ESPRIT 120 ED and 150 ED

PLL-PL3600253

Directly connects the ESATTO 3" robotic focuser to specific telescopes Compatible with Sky-Watcher ESPRIT 120 ED and 150 ED models Enables precise...

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CA$357.00 - CA$357.00
CA$357.00
CA$357.00 - CA$357.00
CA$357.00

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.