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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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Orion Optics UK AG10 Angled Finder 50mm Wide Field
CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00

Orion Optics UK AG10 Angled Finder 50mm Wide Field

OOUK-AG10-ANGLED-FINDER-50MM-WIDE

50mm Aperture 90-Degree Angled Design Fully Coated Optics Integrated Crosshairs for Centering Dovetail Quick-Release Mounting System Descriptio...

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CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00
Orion Optics UK AG10 Equipment upgrade to allow fitting of Atlas focuser
CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00

Orion Optics UK AG10 Equipment upgrade to allow fitting of Atlas focuser

OOUK-AG10-EQUIPMENT-UPGRADE-ALLOW-FITTING

Fits the FLI Atlas focuser to the AG10 Replaces the standard Ceres focuser Individually machined to order in the UK Description Specifications ...

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CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00
Orion Optics UK AG10 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas
CA$1,130.00 - CA$1,130.00
CA$1,130.00
CA$1,130.00 - CA$1,130.00
CA$1,130.00

Orion Optics UK AG10 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas

OOUK-AG10-FOCUSER-STABILISATION-UPGRADE-CNC

For the AG10 astrograph Reinforces focuser and tube-ring positions For the ACU-3 or Atlas focuser Individually machined to order in the UK Desc...

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CA$1,130.00 - CA$1,130.00
CA$1,130.00
CA$1,130.00 - CA$1,130.00
CA$1,130.00
Orion Optics UK AG10 Straight Finder 50mm Wide Field
CA$198.00 - CA$198.00
CA$198.00
CA$218.00
CA$218.00 - CA$218.00
CA$218.00

Orion Optics UK AG10 Straight Finder 50mm Wide Field

OOUK-AG10-STRAIGHT-FINDER-50MM-WIDE

50mm Aperture Straight-Through Optical Design Fully Coated Optics Visible Crosshair Reticle Quick-Release Dovetail Shoe Sprung-Loaded Adjustment S...

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CA$198.00 - CA$198.00
CA$198.00
CA$218.00
CA$218.00 - CA$218.00
CA$218.00
Orion Optics UK AG12 Equipment upgrade to allow fitting of Atlas focuser
CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00

Orion Optics UK AG12 Equipment upgrade to allow fitting of Atlas focuser

OOUK-AG12-EQUIPMENT-UPGRADE-ALLOW-FITTING

Fits the FLI Atlas focuser to the AG12 Replaces the standard Ceres focuser Individually machined to order in the UK Description Specifications ...

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CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00
Orion Optics UK AG12 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas
CA$1,306.00 - CA$1,306.00
CA$1,306.00
CA$1,306.00 - CA$1,306.00
CA$1,306.00

Orion Optics UK AG12 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas

OOUK-AG12-FOCUSER-STABILISATION-UPGRADE-CNC

For the AG12 astrograph Reinforces focuser and tube-ring positions For the ACU-3 or Atlas focuser Individually machined to order in the UK Desc...

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CA$1,306.00 - CA$1,306.00
CA$1,306.00
CA$1,306.00 - CA$1,306.00
CA$1,306.00
Orion Optics UK AG14 Angled Finder 50mm Wide Field
CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00

Orion Optics UK AG14 Angled Finder 50mm Wide Field

OOUK-AG14-ANGLED-FINDER-50MM-WIDE

50mm Aperture Angled Viewing Position Fully Coated Optics Integrated Crosshairs for Centering Designed for Quick-Release Dovetail Shoe Descript...

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CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00
Orion Optics UK AG14 Equipment upgrade to allow fitting of Atlas focuser
CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00

Orion Optics UK AG14 Equipment upgrade to allow fitting of Atlas focuser

OOUK-AG14-EQUIPMENT-UPGRADE-ALLOW-FITTING

Fits the FLI Atlas focuser to the AG14 Replaces the standard Ceres focuser Individually machined to order in the UK Description Specifications ...

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CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00
Orion Optics UK AG14 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas
CA$1,409.00 - CA$1,409.00
CA$1,409.00
CA$1,409.00 - CA$1,409.00
CA$1,409.00

Orion Optics UK AG14 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas

OOUK-AG14-FOCUSER-STABILISATION-UPGRADE-CNC

For the AG14 astrograph Reinforces focuser and tube-ring positions For the ACU-3 or Atlas focuser Individually machined to order in the UK Desc...

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CA$1,409.00 - CA$1,409.00
CA$1,409.00
CA$1,409.00 - CA$1,409.00
CA$1,409.00
Orion Optics UK AG14 Straight finder 50mm wide field
CA$198.00 - CA$198.00
CA$198.00
CA$218.00
CA$218.00 - CA$218.00
CA$218.00

Orion Optics UK AG14 Straight finder 50mm wide field

OOUK-AG14-STRAIGHT-FINDER-50MM-WIDE

50mm Aperture 8x Magnification Straight-Through Optical Path Fully Coated Optics Quick-Release Dovetail Mounting System Description FAQ Specifi...

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CA$198.00 - CA$198.00
CA$198.00
CA$218.00
CA$218.00 - CA$218.00
CA$218.00
Orion Optics UK AG16 50mm Angled Finder Scope
CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00

Orion Optics UK AG16 50mm Angled Finder Scope

OOUK-AG16-ANGLED-FINDER-50MM-WIDE

50mm Aperture 90-Degree Angled Viewing Fully Coated Optics Non-illuminated Crosshair Reticle Designed for Dovetail Mounting Shoes Description F...

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CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00
Orion Optics UK AG16 Equipment upgrade to allow fitting of Atlas focuser
CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00

Orion Optics UK AG16 Equipment upgrade to allow fitting of Atlas focuser

OOUK-AG16-EQUIPMENT-UPGRADE-ALLOW-FITTING

Fits the FLI Atlas focuser to the AG16 Replaces the standard Ceres focuser Individually machined to order in the UK Description Specifications ...

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CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00
Orion Optics UK AG16 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas
CA$1,596.00 - CA$1,596.00
CA$1,596.00
CA$1,596.00 - CA$1,596.00
CA$1,596.00

Orion Optics UK AG16 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas

OOUK-AG16-FOCUSER-STABILISATION-UPGRADE-CNC

For the AG16 astrograph Reinforces focuser and tube-ring positions For the ACU-3 or Atlas focuser Individually machined to order in the UK Desc...

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CA$1,596.00 - CA$1,596.00
CA$1,596.00
CA$1,596.00 - CA$1,596.00
CA$1,596.00
Orion Optics UK AG8 Equipment upgrade to allow fitting of Atlas focuser
CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00

Orion Optics UK AG8 Equipment upgrade to allow fitting of Atlas focuser

OOUK-AG8-EQUIPMENT-UPGRADE-ALLOW-FITTING

Fits the FLI Atlas focuser to the AG8 Replaces the standard Ceres focuser Individually machined to order in the UK Description Specifications I...

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CA$767.00 - CA$767.00
CA$767.00
CA$767.00 - CA$767.00
CA$767.00
Orion Optics UK AG8 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas
CA$974.00 - CA$974.00
CA$974.00
CA$974.00 - CA$974.00
CA$974.00

Orion Optics UK AG8 Focuser stabilisation upgrade and CNC tube ring stability upgrade kit for ACU-3 focuser or Atlas

OOUK-AG8-FOCUSER-STABILISATION-UPGRADE-CNC

For the AG8 astrograph Reinforces focuser and tube-ring positions For the ACU-3 or Atlas focuser Individually machined to order in the UK Descr...

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CA$974.00 - CA$974.00
CA$974.00
CA$974.00 - CA$974.00
CA$974.00
Orion Optics UK AG8 Straight Finder 50mm Wide Field
CA$198.00 - CA$198.00
CA$198.00
CA$218.00
CA$218.00 - CA$218.00
CA$218.00

Orion Optics UK AG8 Straight Finder 50mm Wide Field

OOUK-AG8-STRAIGHT-FINDER-50MM-WIDE

50mm Aperture 8x Magnification Straight-Through Optical Design Fully Coated Optics Quick-Release Dovetail Mounting System Integrated Crosshairs fo...

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CA$198.00 - CA$198.00
CA$198.00
CA$218.00
CA$218.00 - CA$218.00
CA$218.00
Orion Optics UK Angled & Anodised Finder Bracket Holder
CA$135.00 - CA$135.00
CA$135.00
CA$135.00 - CA$135.00
CA$135.00

Orion Optics UK Angled & Anodised Finder Bracket Holder

OOUK-FINDER-BRACKET-HOLDER-ANGLED-ANODISED

Designed specifically for Orion Optics UK ODK telescopes Enables secure mounting of upgraded finderscopes Angled design for improved ergonomics an...

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CA$135.00 - CA$135.00
CA$135.00
CA$135.00 - CA$135.00
CA$135.00
Orion Optics UK Angled Finder 50mm Wide Field
CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00

Orion Optics UK Angled Finder 50mm Wide Field

OOUK-AG8-ANGLED-FINDER-50MM-WIDE

50mm Aperture 90-Degree Angled Viewing Fully Multi-Coated Optics Illuminated Crosshair Reticle Quick-Release Dovetail Shoe Description FAQ Spec...

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CA$218.00 - CA$218.00
CA$218.00
CA$238.00
CA$238.00 - CA$238.00
CA$238.00
Orion Optics UK Atlas ZTA to ODK Cell adpt. Using 15mm BFD
CA$322.00 - CA$322.00
CA$322.00
CA$322.00 - CA$322.00
CA$322.00

Orion Optics UK Atlas ZTA to ODK Cell adpt. Using 15mm BFD

OOUK-ATLAS-ZTA-ODK-CELL-ADPT

Machined to fit ODK Cell adpt 15mm back focal distance For the FLI Atlas focuser system Individually machined to order in the UK Description Sp...

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CA$322.00 - CA$322.00
CA$322.00
CA$322.00 - CA$322.00
CA$322.00
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
Orion Optics UK ODK cell adaptor for Atlas kit using 10mm BFD
CA$425.00 - CA$425.00
CA$425.00
CA$425.00 - CA$425.00
CA$425.00

Orion Optics UK ODK cell adaptor for Atlas kit using 10mm BFD

OOUK-ODK-CELL-ADAPTOR-ATLAS-KIT

Fits the FLI Atlas focuser kit 10mm back focal distance For the ODK Optimised Dall-Kirkham range Individually machined to order in the UK Descr...

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CA$425.00 - CA$425.00
CA$425.00
CA$425.00 - CA$425.00
CA$425.00
Orion Optics UK Straight Finder 50mm Wide Field
CA$198.00 - CA$198.00
CA$198.00
CA$198.00 - CA$198.00
CA$198.00

Orion Optics UK Straight Finder 50mm Wide Field

OOUK-AG16-STRAIGHT-FINDER-50MM-WIDE

50mm Aperture 8x Magnification Straight-Through Optical Design Fully Coated Optics Adjustable Crosshairs Quick-Release Dovetail Mounting Shoe D...

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CA$198.00 - CA$198.00
CA$198.00
CA$198.00 - CA$198.00
CA$198.00
CA$364.00 - CA$364.00
CA$364.00
CA$364.00 - CA$364.00
CA$364.00

Pegasus Astro FocusCube 3 Universal

PEG-FC3-UNIV

High-torque geared stepper motor with 60N.cm of pull-in torque Lifts imaging payloads up to 6 kg USB-C and 2.4GHz WiFi connectivity for OS-indepen...

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CA$364.00 - CA$364.00
CA$364.00
CA$364.00 - CA$364.00
CA$364.00
CA$301.00 - CA$301.00
CA$301.00
CA$301.00 - CA$301.00
CA$301.00

Pegasus Dual Motor Focus Controller

PEG-DMFC

Drives DC motors (up to 1A) and unipolar/bipolar stepper motors (up to 2A) Manual control via digital encoder knob and PC control via USB 2.0 ASCO...

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CA$301.00 - CA$301.00
CA$301.00
CA$301.00 - CA$301.00
CA$301.00

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.