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 Deluxe Clamping Eyepiece Holder - 2"
Securely holds all 2" eyepieces and accessories Non-marring clamping mechanism prevents scratches on barrels Ensures precise and repeatable center...
View full detailsBaader Diamond Steeltrack 2" Focuser for Newtonians
2" Focuser Format Diamond Steeltrack Drive System Designed for Newtonian Telescopes Universal Mounting Base Includes Adjustment Shims Descripti...
View full detailsBaader Diamond Steeltrack 2" Focuser for Refractors
Diamond Steeltrack non-slip drive system Designed for heavy astrophotography payloads 2-inch drawtube with zero image shift Dual-speed mechanism f...
View full detailsBaader Diamond Steeltrack 2" Focuser for SC/HD Telescopes
Precision focuser for Schmidt-Cassegrain & EdgeHD telescopes Eliminates mirror shift for critical focusing Diamond Steeltrack drive system pre...
View full detailsBaader Diascope Bayonet Eyepiece Adapter - 1.25"
Adapts Zeiss Diascope Bayonet to a standard 1.25" eyepiece holder Unlocks access to the entire 1.25" astronomical eyepiece market Enables use of s...
View full detailsBaader Diascope Bayonet Eyepiece Adapter - 2"
Adapts Zeiss Diascope eyepieces to a standard 2" focuser Features the proprietary Zeiss bayonet mount Precision-machined for a secure, non-marring...
View full detailsBaader Expanding Ring - 2" NexStar 4 (C90)/ETX
Converts the rear port thread on Celestron C90, NexStar 4, and Meade ETX telescopes Adapts the proprietary thread to a standard 2" Schmidt-Cassegr...
View full detailsBaader Eyepiece Adapter - 1.25"/M41 Morpheus to Kowa TSN 770/880
Adapts Baader Morpheus eyepieces to Kowa spotting scopes Compatible with Kowa TSN 770 and TSN 880 models Utilizes the M41 thread on Morpheus eyepi...
View full detailsBaader Flat Base Plate for BDS-NT Newtonian Diamond Steeltrack
Adapts Baader BDS-NT Focuser to flat surfaces Ideal for truss-tube Dobsonians and custom astrographs Provides a stable, flush mounting point Repla...
View full detailsBaader Focusing Eyepiece Holder - 1.25"/M36.4(M)
Adds precise focusing to 1.25" eyepieces or accessories Connects to female M36.4 Vixen-style threads Ideal for finderscopes, guidescopes, and othe...
View full detailsBaader Focusing Eyepiece Holder - 1.25"/T-2
Adds precise helical focusing to any T-2 thread Accepts standard 1.25" eyepieces and accessories Dual clampscrews for a balanced, secure hold Inte...
View full detailsBaader Hyperion / Morpheus Extension - M43
Customizes eyecup height for optimal eye placement Provides a secure clamping surface for smartphone adapters Stackable design for eyepiece projec...
View full detailsBaader Hyperion 2" Finetuning Stopring w/Brass Clampring
Makes 2-inch Baader Hyperion eyepieces parfocal Sets a precise, repeatable focus position for each eyepiece Integrated brass clamp ring prevents s...
View full detailsBaader Hyperion Finetuning-Ring - 14mm M48/M48
14mm Extension Length M48 Male and Female Threads Compatible with Baader Hyperion Modular Eyepieces Increases Eyepiece Magnification Maintains Opt...
View full detailsBaader Hyperion Finetuning-Ring - 28mm M48/M48
28mm Optical Extension M48 Male and Female Threads Modifies Eyepiece Focal Length Compatible with Baader Hyperion Eyepieces Maintains Optical Alig...
View full detailsBaader Hyperion Zoom Mark IV to M54 Kowa TSN 770/880
Connects Baader Hyperion Zoom Mark IV to Kowa spotting scopes Designed for Kowa TSN 770 and TSN 880 series Utilizes the scope's native M54 male th...
View full detailsBaader Log-Pot Illuminator for MicroGuide and older Baader Finders
Variable brightness illuminator Logarithmic potentiometer for fine control at low brightness Designed for Baader MicroGuide eyepieces Compatible w...
View full detailsBaader Multipurpose Finder Bracket MQR III 7x50 (max 62mm)
CNC Milled Construction for Rigidity Quick-Release Dovetail for Repeatable Alignment Modular Design Adapts to Finderscopes or Red-Dot Sights Fits ...
View full detailsBaader Multipurpose Finder Bracket MQR IV 7x50 (max 72mm)
Accommodates finder scopes up to 72mm in diameter CNC-milled quick-release dovetail for precise return-to-zero alignment Modular design allows for...
View full detailsBaader Nosepiece Extension - 1.25"
Adds 18mm of extension length Standard 1.25" outer diameter Threads into 1.25" eyepiece filter threads Features male and female 1.25" filter threa...
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Baader Planetarium 2" Deluxe Eyepiece Clamp for SC-telescopes – with 2" filter thread
Baader Planetarium 2" Deluxe Eyepiece Clamp for SC-telescopes – with 2" filter thread
Adapts Schmidt-Cassegrain telescopes to use 2-inch accessories Internal 2-inch filter thread for optical tube protection Securely holds heavy diag...
View full detailsBaader Planetarium 2" Deluxe Eyepiece Clamp for SC-telescopes – with 2" Nosepiece
Adds 60mm of optical length to the light path Securely clamps 2-inch eyepieces and accessories Integrated dual 2-inch filter holder Connects to st...
View full detailsBaader Planetarium 2" Nosepiece to M45a – for Hyperion® Zoom MK III
Converts the Hyperion® Zoom MK III eyepiece to a native 2" barrel Threads directly to the eyepiece's M45a body thread Eliminates the need for a se...
View full detailsBaader Planetarium Adapter D60 (Pentax) to 2" Nosepiece
Adapts female Pentax D60 threads to a male 2" nosepiece Enables the use of standard 2" diagonals, eyepieces, and camera adapters Provides a secure...
View full detailsFocuser 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.