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Focusers

At f/4, the critical focus zone is a few tens of microns. A metal telescope tube contracting through a fifteen-degree Canadian night will move focus well outside that on its own, which is why motorized, temperature-compensated focus stopped being a luxury for imagers. David Astro carries focusers in Canada — manual dual-speed, stepper-driven and fully robotic — in Canadian inventory and shipped domestically.

Fit and load capacity are the two decisions that matter. Tell us your telescope and the weight of your camera train and we will specify the focuser and the mounting adapter together.

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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 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$503.00 - CA$503.00
CA$503.00
CA$503.00 - CA$503.00
CA$503.00

Baader Diamond Steeltrack 2" Focuser for Newtonians

BAA-2957230

2" Focuser Format Diamond Steeltrack Drive System Designed for Newtonian Telescopes Universal Mounting Base Includes Adjustment Shims Descripti...

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CA$503.00 - CA$503.00
CA$503.00
CA$503.00 - CA$503.00
CA$503.00
CA$523.00 - CA$523.00
CA$523.00
CA$523.00 - CA$523.00
CA$523.00

Baader Diamond Steeltrack 2" Focuser for Refractors

BAA-2957210

Diamond Steeltrack non-slip drive system Designed for heavy astrophotography payloads 2-inch drawtube with zero image shift Dual-speed mechanism f...

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CA$523.00 - CA$523.00
CA$523.00
CA$523.00 - CA$523.00
CA$523.00
CA$532.00 - CA$532.00
CA$532.00
CA$532.00 - CA$532.00
CA$532.00

Baader Diamond Steeltrack 2" Focuser for SC/HD Telescopes

BAA-2957220
2 in stock

Precision focuser for Schmidt-Cassegrain & EdgeHD telescopes Eliminates mirror shift for critical focusing Diamond Steeltrack drive system pre...

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CA$532.00 - CA$532.00
CA$532.00
CA$532.00 - CA$532.00
CA$532.00
Explore Scientific 3-inch Self-Centering Focuser
CA$1,190.00 - CA$1,190.00
CA$1,190.00
CA$1,190.00 - CA$1,190.00
CA$1,190.00

Explore Scientific 3-inch Self-Centering Focuser

ES-FOC3

3-inch self-centering draw tube 17 lb (7.7 kg) lifting capacity 9:1 dual-speed focusing system 84.5mm of precision draw tube travel Rotatable back...

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CA$1,190.00 - CA$1,190.00
CA$1,190.00
CA$1,190.00 - CA$1,190.00
CA$1,190.00
Explore Scientific 3-inch Self-Centering Focuser with Back Cell Adapter for FCD100-127-CF
CA$1,400.00 - CA$1,400.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00

Explore Scientific 3-inch Self-Centering Focuser with Back Cell Adapter for FCD100-127-CF

ES-FOC3-BC100127

3-inch Self-Centering Focuser Design 17 lb Lifting Capacity for Heavy Imaging Trains 9:1 Dual-Speed Helical Rack-and-Pinion Mechanism 84.5mm of Pr...

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CA$1,400.00 - CA$1,400.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00
Explore Scientific 3-inch Self-Centering Focuser with Back Cell Adapter for White Tube ED127 and FCD-100
CA$1,400.00 - CA$1,400.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00

Explore Scientific 3-inch Self-Centering Focuser with Back Cell Adapter for White Tube ED127 and FCD-100

ES-FOC3-BC100127T

Designed for Explore Scientific white-tube ED127 and FCD-100 refractors 17 lb instrument lifting capacity Self-centering compression system elimin...

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CA$1,400.00 - CA$1,400.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00
CA$419.99 - CA$419.99
CA$419.99
CA$419.99 - CA$419.99
CA$419.99

Explore Scientific APO EDT Series Rack & Pinion Focuser

ES-FOCEDAPO-RP

2" Diameter Rack & Pinion Focuser 10:1 Dual-Speed Fine Focus Control Weighs 2.0lb (.91kg) Includes 1.25" Compression Ring Adapter Three Lockin...

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CA$419.99 - CA$419.99
CA$419.99
CA$419.99 - CA$419.99
CA$419.99
iOptron Electronic Automatic Focuser - iEAF
CA$279.00 - CA$279.00
CA$279.00
CA$279.00 - CA$279.00
CA$279.00

iOptron Electronic Automatic Focuser - iEAF

IOP-8453

5 kg Maximum Payload Capacity High-Precision Stepper Motor Drive Built-in Temperature Sensor for Focus Compensation ASCOM Compatible for Automated...

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CA$279.00 - CA$279.00
CA$279.00
CA$279.00 - CA$279.00
CA$279.00
iOptron iAFS2 - iOptron 2'' Inline Automatic Focuser
CA$643.00 - CA$643.00
CA$643.00
CA$643.00 - CA$643.00
CA$643.00

iOptron iAFS2 - iOptron 2'' Inline Automatic Focuser

IOP-FA20

Supports a maximum payload of 5kg without slippage Delivers 0.6µm focusing resolution for critical imaging Features a 51mm clear aperture for full...

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CA$643.00 - CA$643.00
CA$643.00
CA$643.00 - CA$643.00
CA$643.00
iOptron iAFS3 - 3-inch Inline Automatic Focuser
CA$755.00 - CA$755.00
CA$755.00
CA$755.00 - CA$755.00
CA$755.00

iOptron iAFS3 - 3-inch Inline Automatic Focuser

IOP-FA30

3-inch inline auto focuser with iLock™ technology Supports heavy imaging payloads up to 6kg 68mm clear aperture minimizes vignetting Precise 0.4um...

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CA$755.00 - CA$755.00
CA$755.00
CA$755.00 - CA$755.00
CA$755.00
CA$525.00 - CA$525.00
CA$525.00
CA$525.00 - CA$525.00
CA$525.00

Lunt Backing Plate & Focuser - LS100MT

LSS-BP&F/LS100MT

Official Lunt Solar Systems Replacement Part Designed Exclusively for the LS100MT Telescope Includes Focuser and Backing Plate Assembly Restores O...

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CA$525.00 - CA$525.00
CA$525.00
CA$525.00 - CA$525.00
CA$525.00
CA$517.00 - CA$517.00
CA$517.00
CA$517.00 - CA$517.00
CA$517.00

Lunt Backing Plate & Focuser - LS152T

LSS-LS152T/BP&F

Converts the Lunt LS152THa solar telescope for nighttime astronomical use Replaces the rear pressure-tuner assembly Features a precision 2" Crayfo...

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CA$517.00 - CA$517.00
CA$517.00
CA$517.00 - CA$517.00
CA$517.00
CA$525.00 - CA$525.00
CA$525.00
CA$525.00 - CA$525.00
CA$525.00

Lunt Backing Plate & Focuser - LS80MT

LSS-BP&F/LS80MT

Enables nighttime astronomical observing with the LS80MT Required for white-light solar viewing with a solar wedge Replaces the primary H-alpha tu...

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CA$525.00 - CA$525.00
CA$525.00
CA$525.00 - CA$525.00
CA$525.00
CA$119.00 - CA$119.00
CA$119.00
CA$119.00 - CA$119.00
CA$119.00

Lunt Mini Helical Focuser - 1.25"

LSS-LSMINI/1.25

1.25" Helical Focuser Non-Rotating Mechanism T2 Male and T2 Female Threads Brass Compression Ring Locking Collar for Secure Focus Description F...

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CA$119.00 - CA$119.00
CA$119.00
CA$119.00 - CA$119.00
CA$119.00
CA$376.00 - CA$376.00
CA$376.00
CA$376.00 - CA$376.00
CA$376.00

Lunt Solar 1.25" R&P Focuser - Dual Speed

LSS-001-148
1 in stock

1.25" Focuser Size 10:1 Dual-Speed Reduction Fine Focus 6-8 pound (2.7-3.6 kg) Load Capacity 0.5" Draw Tube Travel CNC Machined Aluminum and Brass...

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CA$376.00 - CA$376.00
CA$376.00
CA$376.00 - CA$376.00
CA$376.00
CA$237.00 - CA$237.00
CA$237.00
CA$237.00 - CA$237.00
CA$237.00

Lunt Solar 1.25" R&P Focuser - Single Speed

LSS-001-147

Replaces stock helical focusers on Lunt Solar telescopes 1.25" eyepiece and accessory holder Rack and Pinion mechanism eliminates backlash and ima...

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CA$237.00 - CA$237.00
CA$237.00
CA$237.00 - CA$237.00
CA$237.00
CA$5,033.00 - CA$5,033.00
CA$5,033.00
CA$5,033.00 - CA$5,033.00
CA$5,033.00

Optec Gemini Focusing Rotator

OPC-19750

Optec engineers have developed a completely new concept for combining telescope focus and camera rotation functions into a single robust, yet compa...

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CA$5,033.00 - CA$5,033.00
CA$5,033.00
CA$5,033.00 - CA$5,033.00
CA$5,033.00
CA$1,813.00 - CA$2,093.00
CA$1,813.00 - CA$2,093.00
CA$1,813.00 - CA$2,093.00
CA$1,813.00

Optec TCF-Leo Low Profile Focuser

Options available

Optec engineers have developed a low profile, yet extremely robust 3-inch focuser for telescope installations where back-focus is at a premium. Wi...

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CA$1,813.00 - CA$2,093.00
CA$1,813.00 - CA$2,093.00
CA$1,813.00 - CA$2,093.00
CA$1,813.00
Orion Optics UK Eris 2" R+P focuser
CA$999.00 - CA$999.00
CA$999.00
CA$999.00 - CA$999.00
CA$999.00

Orion Optics UK Eris 2" R+P focuser

OOUK-ERIS-2-R-P-FOCUSER

2" rack-and-pinion focuser Smooth lock Standard on the IDEAL and VX ranges Description Specifications In the Box Warranty Eris 2" R+P Foc...

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CA$999.00 - CA$999.00
CA$999.00
CA$999.00 - CA$999.00
CA$999.00
PrimaLuceLab ESATTO 2" Focuser with ARCO 2" Rotator
CA$1,987.00 - CA$1,987.00
CA$1,987.00
CA$1,987.00 - CA$1,987.00
CA$1,987.00

PrimaLuceLab ESATTO 2" Focuser with ARCO 2" Rotator

PLLEST2ARCO2

Combines robotic focuser and high-precision rotator in one unit Low-profile design for minimal back focus consumption Single-cable connection betw...

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CA$1,987.00 - CA$1,987.00
CA$1,987.00
CA$1,987.00 - CA$1,987.00
CA$1,987.00
PrimaLuceLab ESATTO 2" LP Focuser with ARCO 2" Rotator
CA$2,331.00 - CA$2,331.00
CA$2,331.00
CA$2,331.00 - CA$2,331.00
CA$2,331.00

PrimaLuceLab ESATTO 2" LP Focuser with ARCO 2" Rotator

PLLEST2LPARCO2

Combines ESATTO 2" LP robotic focuser and ARCO 2" robotic rotator Low-profile design for compact imaging trains Unified power and data connection ...

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CA$2,331.00 - CA$2,331.00
CA$2,331.00
CA$2,331.00 - CA$2,331.00
CA$2,331.00
CA$1,225.00 - CA$1,225.00
CA$1,225.00
CA$1,225.00 - CA$1,225.00
CA$1,225.00

PrimaLuceLab ESATTO 2" LP low profile robotic focuser

PLLEST2LP-B

Ultra-low 32mm profile designed for low-backfocus telescopes 10mm of precise focuser travel 5 kg (11 lbs) payload capacity for heavy imaging train...

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CA$1,225.00 - CA$1,225.00
CA$1,225.00
CA$1,225.00 - CA$1,225.00
CA$1,225.00

Manual, Motorized and Robotic Focus

All focusers move a drawtube. What separates them is how much they can hold without slipping and how repeatably they can return to a position.

  • Dual-speed manual focusers: Coarse and 10:1 fine focus, entirely adequate for visual observing and for imaging where you are willing to refocus by hand periodically.
  • Stepper motor focusers: Absolute positioning with repeatable steps, enabling automated focus routines and per-filter focus offsets.
  • Robotic microfocusers: High load capacity with integrated temperature sensing and position feedback, designed for unattended operation across a whole night.
  • Load capacity: The specification that matters most for imaging. A camera, filter wheel, off-axis guider and adapters add up quickly, and the load acts as a bending moment when the tube is horizontal.
  • Travel and profile height: A replacement focuser with a taller profile can prevent a telescope reaching focus, particularly on Newtonians. This must be checked before purchase.
  • Temperature compensation: A sensor and coefficient that shift focus automatically as the tube cools, which removes the largest single source of overnight focus drift.

Why Choose David Astro for Focusers

A focuser is a retrofit, and retrofits fail on details that are easy to check beforehand.

  • Focus travel verified: We check that the new focuser's profile still allows your telescope to reach focus with your intended camera or diagonal, which is the most common retrofit failure.
  • Adapter identified: We specify the telescope-specific mounting flange alongside the focuser, so the parts arrive complete.
  • Load calculated with the moment arm: We consider the weight and its distance from the drawtube, not just the total mass.
  • Authorized dealer: Full manufacturer warranty with service handled in Canada.
  • Canadian stock: Ships domestically without duties or brokerage fees for Canadian orders.

Focusers in Canada — Frequently Asked Questions

Do I need an electronic focuser?
For imaging below about f/6, yes in practice. Focus shift with temperature exceeds the critical focus zone over a Canadian night, and refocusing manually every hour costs you exposures and disturbs the rig.
Will a new focuser fit my Newtonian?
Only if its profile height is compatible. A taller focuser can push the focal plane beyond the drawtube's inward travel. Tell us the telescope and we will check before you order.
How much load can a focuser really take?
Rated capacities usually assume the tube pointing up. Near the horizon the same weight acts as a bending moment and effective capacity drops. We size with margin for that.
Can I add temperature compensation later?
On most stepper-based systems, yes — a temperature probe and a measured coefficient are all that is required. We can help determine the coefficient for your specific tube.

Replacing a focuser?

Send us your telescope and imaging train weight and we will specify the focuser and flange. Ships from our Canadian warehouse.