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Porte-oculaires et accessoires

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.

Filtres

Baader Planetarium Adapter S58-short to M54a – for all BDS Diamond Steeltrack®
$50.00 - $50.00
$50.00
$50.00 - $50.00
$50.00

Baader Planetarium Adapter S58-short to M54a – for all BDS Diamond Steeltrack®

BAA-2957209

Adapts the Baader S58 drawtube thread to a female M54a thread Designed for all Baader Diamond Steeltrack® (BDS) focusers Enables direct connection...

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$50.00 - $50.00
$50.00
$50.00 - $50.00
$50.00
Baader Planetarium Adapter S58-short to M68i – for all BDS Diamond Steeltrack®
$86.00 - $86.00
$86.00
$86.00 - $86.00
$86.00

Baader Planetarium Adapter S58-short to M68i – for all BDS Diamond Steeltrack®

BAA-2957207

Adapts the Baader S58 dovetail thread to M68i Provides a secure, rigid M68i female (internal) thread connection Designed for all Baader Diamond St...

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$86.00 - $86.00
$86.00
$86.00 - $86.00
$86.00
Baader Planetarium BDS-SC Adapter S88i to M48i
$156.00 - $156.00
$156.00
$156.00 - $156.00
$156.00

Baader Planetarium BDS-SC Adapter S88i to M48i

BAA-2957297

Connects Baader Diamond Steeltrack SC (BDS-SC) focusers to M48 accessories Provides a standard female M48 (M48x0.75) accessory thread Enables a ri...

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$156.00 - $156.00
$156.00
$156.00 - $156.00
$156.00
Baader Planetarium Mark IV Zoom Adapter to M45 – for Zeiss-Diascope
$75.00 - $75.00
$75.00
$75.00 - $75.00
$75.00

Baader Planetarium Mark IV Zoom Adapter to M45 – for Zeiss-Diascope

BAA-2454831

Adapts Baader Hyperion Mark IV Zoom eyepiece to Zeiss Diascopes Provides a secure M45x0.5 threaded connection Ensures perfect optical alignment Re...

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$75.00 - $75.00
$75.00
$75.00 - $75.00
$75.00
Baader Planetarium Sky Surfer III – Adapter for large telescopes made of ABS
$9.00 - $9.00
$9.00
$9.00 - $9.00
$9.00

Baader Planetarium Sky Surfer III – Adapter for large telescopes made of ABS

BAA-2957304

Securely mounts the Baader Sky Surfer III finder Designed for use on large telescope optical tubes Constructed from durable, lightweight ABS plast...

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$9.00 - $9.00
$9.00
$9.00 - $9.00
$9.00
Baader Planetarium Sky Surfer III – Flat base adapter made of ABS
$8.50 - $8.50
$8.50
$8.50 - $8.50
$8.50

Baader Planetarium Sky Surfer III – Flat base adapter made of ABS

BAA-2957302

Adapts Sky Surfer III for flat-surface mounting Enables use on square tube telescopes and mounting rings Constructed from durable, lightweight ABS...

Afficher tous les détails
$8.50 - $8.50
$8.50
$8.50 - $8.50
$8.50
Baader Planetarium Steeldrive II Adapter set for FeatherTouch 3.5" focusers
$139.00 - $139.00
$139.00
$139.00 - $139.00
$139.00

Baader Planetarium Steeldrive II Adapter set for FeatherTouch 3.5" focusers

BAA-2957270

Enables motorization of FeatherTouch 3.5" focusers Designed for the Baader Steeldrive II motor Provides a secure, no-slip mechanical coupling Faci...

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$139.00 - $139.00
$139.00
$139.00 - $139.00
$139.00
Baader Planetarium Steeldrive II Belt Cover – 3D-printed
$64.00 - $64.00
$64.00
$64.00 - $64.00
$64.00

Baader Planetarium Steeldrive II Belt Cover – 3D-printed

BAA-2957259

Protects Steeldrive II belt and pulleys Shields drive system from dew, dust, and debris Prevents accidental snags on cables or clothing Custom-des...

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$64.00 - $64.00
$64.00
$64.00 - $64.00
$64.00
Baader Planetarium Baader Steeldrive II Controller
$522.00 - $522.00
$522.00
$522.00 - $522.00
$522.00

Baader Planetarium Steeldrive II Controller

BAA-2957260

Standalone hand controller for Baader Steeldrive II motor units Three distinct, selectable focusing modes for any scenario Full computer control a...

Afficher tous les détails
$522.00 - $522.00
$522.00
$522.00 - $522.00
$522.00
Baader Planetarium Baader Steeldrive II Motor Unit
$325.00 - $325.00
$325.00
$325.00 - $325.00
$325.00

Baader Planetarium Steeldrive II Motor Unit

BAA-2957265

High-torque stepper motor handles heavy imaging loads Timing belt drive eliminates backlash for precise autofocus Contactless homing sensor enable...

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$325.00 - $325.00
$325.00
$325.00 - $325.00
$325.00
Baader Planetarium Universal Red Dot Mount RDM
$61.00 - $61.00
$61.00
$61.00 - $61.00
$61.00

Baader Planetarium Universal Red Dot Mount RDM

BAA-2457010

Adapts 11mm Weaver-rail finders to standard Vixen/Synta-style finder shoes 70mm riser height for comfortable head positioning Durable all-metal co...

Afficher tous les détails
$61.00 - $61.00
$61.00
$61.00 - $61.00
$61.00
$70.00 - $70.00
$70.00
$70.00 - $70.00
$70.00

Baader Adaptateur Pushfix Low Profile - 1.25"/2" pour Porte-Oculaires Steeltrack NT

BAA-2408151

Idéal pour les porte-oculaires Newton, par exemple les porte-oculaires Baader Newton Crayford avec une longueur de chemin optique de seulement 1 ...

Afficher tous les détails
$70.00 - $70.00
$70.00
$70.00 - $70.00
$70.00
$81.00 - $81.00
$81.00
$81.00 - $81.00
$81.00

Baader Q-Turret Revolver à Quatre Oculaires - 1.25"

BAA-2957010
1 en stock

Le Baader Q-Turret permet un changement rapide entre les différents oculaires de 1,25 pouces ou une caméra planétaire. Il s'adapte à la plupart de...

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$81.00 - $81.00
$81.00
$81.00 - $81.00
$81.00
$291.00 - $291.00
$291.00
$291.00 - $291.00
$291.00

Baader Adaptateur-RT Diamond Steeltrack - 4.2" Explore Scientific

BAA-2957285

Pour se connecter aux réfracteurs Explore Scientific avec un diamètre extérieur de 4,2" et d'autres télescopes avec un diamètre de tube intérieur...

Afficher tous les détails
$291.00 - $291.00
$291.00
$291.00 - $291.00
$291.00
$156.00 - $156.00
$156.00
$156.00 - $156.00
$156.00

Baader Adaptateur RT Diamond Steeltrack - Intes Micro D66

BAA-2957296

Pour se connecter à Intes Micro avec bride D66 Convient uniquement au BDS-RT Diamond Steeltrack® pour réfracteurs

$156.00 - $156.00
$156.00
$156.00 - $156.00
$156.00
$189.00 - $189.00
$189.00
$189.00 - $189.00
$189.00

Baader Adaptateur-RT Diamond Steeltrack pour Réfracteurs - M93x1(F)

BAA-2957281

Pour connecter des réfracteurs avec des filetages intérieurs M93x1 Convient uniquement au BDS-RT Diamond Steeltrack® pour réfracteurs

$189.00 - $189.00
$189.00
$189.00 - $189.00
$189.00
$63.00 - $63.00
$63.00
$63.00 - $63.00
$63.00

Baader Adaptateur-RT Diamond Steeltrack pour Réfracteurs Sky-Watcher - M90x1(F)

BAA-2957283

Pour se connecter aux réfracteurs Skywatcher avec filetage extérieur M90x1 Convient uniquement au BDS-RT Diamond Steeltrack® pour réfracteurs C...

Afficher tous les détails
$63.00 - $63.00
$63.00
$63.00 - $63.00
$63.00
$66.00 - $66.00
$66.00
$66.00 - $66.00
$66.00

Baader Adaptateur-RT Diamond Steeltrack pour Réfracteurs Sky-Watcher - M90x1.5(M)

BAA-2957284

Pour se connecter aux réfracteurs Skywatcher avec filetage extérieur M90x1,5 Convient uniquement au BDS-RT Diamond Steeltrack® pour réfracteurs

$66.00 - $66.00
$66.00
$66.00 - $66.00
$66.00
$71.00 - $71.00
$71.00
$71.00 - $71.00
$71.00

Baader Adaptateur-RT Diamond Steeltrack pour Réfracteurs Synta/Celestron - Ø97mm

BAA-2957282

Pour connecter des réfracteurs avec un diamètre intérieur de 97 mm Raccord pour de nombreux tubes Synta et Celestron Convient uniquement au BDS...

Afficher tous les détails
$71.00 - $71.00
$71.00
$71.00 - $71.00
$71.00
$153.00 - $153.00
$153.00
$153.00 - $153.00
$153.00

Baader Adaptateur-RT Diamond Steeltrack pour Réfracteurs Vixen - M88x1(F)

BAA-2957280

Pour se connecter sur les réfracteurs Vixen avec filetage intérieur M88x1 Convient uniquement au BDS-RT Diamond Steeltrack® pour réfracteurs

$153.00 - $153.00
$153.00
$153.00 - $153.00
$153.00
$221.00 - $221.00
$221.00
$221.00 - $221.00
$221.00

Baader Adaptateur-SC Diamond Steeltrack - 4" Meade

BAA-2957295

Pour se connecter aux instruments Meade avec filetage intérieur de 4" Convient uniquement au BDS-SC Diamond Steeltrack® pour SC

$221.00 - $221.00
$221.00
$221.00 - $221.00
$221.00
$11.50 - $11.50
$11.50
$11.50 - $11.50
$11.50

Baader Adaptateur Sky Surfer III pour Jumelles

BAA-2957305
1 en stock

Adaptateur binoculaire en ABS, pour Sky-Surfer III pour jumelles avec filetage avant pour trépied Prix ​​unique. Inclus dans la livraison de Sk...

Afficher tous les détails
$11.50 - $11.50
$11.50
$11.50 - $11.50
$11.50
$11.00 - $11.00
$11.00
$11.00 - $11.00
$11.00

Baader Adaptateur Sky Surfer III pour Lunettes de Repérage

BAA-2957306

Adaptateur pour longues-vues en ABS, pour Sky-Surfer III à monter entre la longue-vue et le trépied photo Prix ​​unique. Inclus dans la livrai...

Afficher tous les détails
$11.00 - $11.00
$11.00
$11.00 - $11.00
$11.00
$67.00 - $67.00
$67.00
$67.00 - $67.00
$67.00

Baader Chercheur Point Rouge de 30mm Sky Surfer III

BAA-2957300
2 en stock

Il semble que tout le monde propose un certain type de détecteur de points rouges à faible coût ces jours-ci. Le coût relativement faible et la fa...

Afficher tous les détails
$67.00 - $67.00
$67.00
$67.00 - $67.00
$67.00

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.