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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

$593.00 - $593.00
$593.00
$593.00 - $593.00
$593.00

APM Porte-Oculaire de Luxe 3.7" ZTA

APM-37-Deluxe
1 restant!

APM 3.7" Rack and Pinion Deluxe Focuser Le nouveau porte-oculaire 3,7" est de type crémaillère et pignon, avec mise au point 1:10. Il reste rigide ...

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$593.00 - $593.00
$593.00
$593.00 - $593.00
$593.00
Askar 50P AF KIT
$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00

Askar 50P AF KIT

ASK-50P-AFKIT
5 en stock

Enables automated focusing for the Askar 50P astrograph Compatible with almost all brands of electronic focusers Eliminates manual focus adjustmen...

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$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00
Askar ACL200 AF Kit
$108.00 - $108.00
$108.00
$108.00 - $108.00
$108.00

Askar ACL200 AF Kit

ASK-ASKAREAFKIT
1 en stock

Adds electronic autofocus capability to the Askar ACL200 lens Designed for seamless integration with ZWO EAF and other electronic focusers Include...

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$108.00 - $108.00
$108.00
$108.00 - $108.00
$108.00
$87.00 - $87.00
$87.00
$87.00 - $87.00
$87.00

Askar AF Kit for FMA180 Pro

ASK-ASKAF180P
1 en stock

Enables Electronic Autofocus on the Askar FMA180 Pro Designed for Seamless Integration with ZWO EAF Broadly Compatible with Most Electronic Focuse...

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$87.00 - $87.00
$87.00
$87.00 - $87.00
$87.00
Askar FRA400C AF Kit
$29.00 - $29.00
$29.00
$29.00 - $29.00
$29.00

Askar FRA400C AF Kit

ASK-FRA400C-AFKIT

Enables Automatic Focusing on the Askar FRA400C Compatible with Most Brands of Electronic Focusers Includes Five Synchronous Belts for a Secure Fi...

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$29.00 - $29.00
$29.00
$29.00 - $29.00
$29.00
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Plaque de recherche multi-connexion Askar 150

ASK-MCP150
2 en stock

Ajout polyvalent à votre configuration. 150mm de longueur Excellente stabilité et soutien Description Améliorez la config...

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$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
$34.00 - $34.00
$34.00
$34.00 - $34.00
$34.00

Plaque de recherche multi-connexion Askar 90

ASK-ASKARMCP90
1 en stock

Ajout polyvalent à votre configuration. longueur 90 mm Excellente stabilité et soutien Description Améliorez la configura...

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$34.00 - $34.00
$34.00
$34.00 - $34.00
$34.00
$87.00 - $87.00
$87.00
$87.00 - $87.00
$87.00

Askar SQA55 Autofocus Kit

ASK-SQA55AFKIT

Designed specifically for the Askar SQA55 Astrograph Enables autofocus with nearly all brands of electronic focusers Includes 4 MXL belts and 2 pu...

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$87.00 - $87.00
$87.00
$87.00 - $87.00
$87.00
Askar Worm-and-Gear Automatic Telescope Focuser (WAF)
$199.00 - $199.00
$199.00
$199.00 - $199.00
$199.00

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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$199.00 - $199.00
$199.00
$199.00 - $199.00
$199.00
$49.00 - $49.00
$49.00
$49.00 - $49.00
$49.00

Baader Porte-Oculaire à Serrage Annulaire Ultra-Court - 1.25"/T-2

BAA-2458121

Pince oculaire ultra courte 1¼" (avec anneau de verrouillage en laiton) Longueur optique : 20 mm Optimisé pour guider la caméra, w. trois vis d...

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$49.00 - $49.00
$49.00
$49.00 - $49.00
$49.00
$134.00 - $134.00
$134.00
$134.00 - $134.00
$134.00

Baader Bague à Serrage Annulaire Ultrashort - 2" /M68x1(M)/M60x0.75(M)

BAA-2458196

Pince oculaire Baader Ultrashort 2" Pince oculaire Baader Ultrashort 2" (12 mm backfocus) à monter sur le filetage du système Carl Zeiss M68. Les ...

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$134.00 - $134.00
$134.00
$134.00 - $134.00
$134.00
$139.00 - $139.00
$139.00
$139.00 - $139.00
$139.00

Baader Porte-Oculaire à Serrage Annulaire 4 en 1 - 2" M68 (Zeiss)/2,7" (A.P.)/M60 (Vixen)/M56 (Synta)

BAA-2458190
1 en stock

Porte-oculaire de serrage de 2 "avec anneau de serrage interne en bronze non marquant et deux grandes vis à oreilles. Convient à tous les instr...

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$139.00 - $139.00
$139.00
$139.00 - $139.00
$139.00
$71.00 - $71.00
$71.00
$71.00 - $71.00
$71.00

Baader Bague de Verrouillage 2" pour SCT 8"/9,25"/11"/14"

BAA-2458270
1 en stock

Permet la connexion directe des prismes zénithaux Baader 2" et des miroirs aux télescopes Schmidt-Cassegrain. Pour Celestron SCT 8/9.25/11/14 av...

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$71.00 - $71.00
$71.00
$71.00 - $71.00
$71.00
$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00

Baader Adaptateur - 1.25"/0.965"

BAA-2408191

Réducteur de barillet d'oculaire, 1¼ "à 0,965" (24,5 mm) Filetage M28.5 pour filtres 1¼" Pour utiliser des oculaires de 0,965" (24,5 mm) dans d...

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$62.00 - $62.00
$62.00
$62.00 - $62.00
$62.00
$67.00 - $67.00
$67.00
$67.00 - $67.00
$67.00

Baader Adaptateur - 1.25"/2" " avec Filetage T-2

BAA-2408190

Réducteur de filetage extérieur 2" vers filetage intérieur 1 ¼" / adaptateur d'oculaire Poignée solide avec 2 vis et bague de compression en br...

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$67.00 - $67.00
$67.00
$67.00 - $67.00
$67.00
$79.00 - $79.00
$79.00
$79.00 - $79.00
$79.00

Baader Adaptateur - 2" NexStar 4 (C90)/ETX

BAA-2958500

Adaptateur photo T-2 avec filetage femelle 2" Incl. Porte-filtre 1¼" Adaptateur photo universel NX4 (C90) / ETX (et SC !)

$79.00 - $79.00
$79.00
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$79.00
$37.00 - $37.00
$37.00
$37.00 - $37.00
$37.00

Baader Adaptateur Diamond Steeltrack - M48x0.75(M)

BAA-2957204

Adaptateur BDS avec filetage extérieur M48 pour connecter des pièces M48 Se monte à la place du collier standard avec la bague queue d'aronde S...

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$37.00 - $37.00
$37.00
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$37.00
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$36.00
$36.00 - $36.00
$36.00

Baader Adaptateur Diamond Steeltrack - T-2(M)

BAA-2957202

Adaptateur BDS avec filetage extérieur T-2 pour connecter des pièces T-2 Se monte à la place du collier standard avec la bague queue d'aronde S5...

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$36.00 - $36.00
$36.00
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$36.00
$52.00 - $52.00
$52.00
$52.00 - $52.00
$52.00

Baader Adaptateur Diamond Steeltrack -M68x0.75(M)

BAA-2957206

Adaptateur BDS avec filetage extérieur M68 pour connecter des pièces M68 Se monte à la place du collier standard avec la bague queue d'aronde S5...

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$52.00 - $52.00
$52.00
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$52.00
$33.00 - $33.00
$33.00
$33.00 - $33.00
$33.00

Baader Adaptateur NT Steeltrack - 2"/1.25"

BAA-2408152

Réducteur spécial 2" / 1¼" avec hauteur optique de 4,5 mm uniquement Convient pour BDS-NT Diamond Steeltrack Comprend un porte-filtre de 2" (fi...

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$33.00 - $33.00
$33.00
$33.00 - $33.00
$33.00
$32.00 - $32.00
$32.00
$32.00 - $32.00
$32.00

Baader Porte-Oculaire Budget -1.25"/T-2

BAA-2458120
1 en stock

Oculaire 1¼ "/ filetage intérieur T-2, version économique avec vis M 4 (alternative: composant T-2 # 08A) 1 vis de serrage M4 Côté télescope av...

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$32.00 - $32.00
$32.00
$32.00 - $32.00
$32.00
$98.00 - $98.00
$98.00
$98.00 - $98.00
$98.00

Baader Adaptateur ClickLock - 1.25" /2"

BAA-2956214
1 en stock

Jamais auparavant une pince à oculaire pour l'astronomie amateur n'avait été aussi élaborée. Depuis que Baader Planetarium a présenté pour la prem...

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$98.00 - $98.00
$98.00
$98.00 - $98.00
$98.00
$109.00 - $109.00
$109.00
$109.00 - $109.00
$109.00

Baader Bague à Serrage Annulaire ClickLock - 1.25"/T-2

BAA-2458100
1 en stock

La pince d'oculaire Baader Planetarium Click-Lock (# T2-08) est un porte-oculaire de serrage de précision qui vous permet d'insérer vos oculaires ...

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$109.00 - $109.00
$109.00
$109.00 - $109.00
$109.00
$106.00 - $237.00
$106.00 - $237.00
$106.00 - $237.00
$106.00

Baader Porte-Oculaire ClickLock - de T-2 à 4,1"

Options available
14 variants in stock

L'attente est terminée. Baader Planetarium a développé le grand frère de sa célèbre pince Clicklock 1¼". La nouvelle pince d'oculaire Clicklock de...

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$106.00 - $237.00
$106.00 - $237.00
$106.00 - $237.00
$106.00

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.