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Catadioptriques

A catadioptric telescope folds a long focal length into a tube you can carry with one hand. An 8 inch Schmidt-Cassegrain delivers 2000 mm of focal length in a package shorter than most 80 mm refractors, which is what makes it the standard instrument for planetary detail, lunar work and small galaxies from a suburban backyard. David Astro carries Schmidt-Cassegrain and Maksutov telescopes in Canada, in stock and shipped from our Canadian warehouse.

These designs trade some contrast for their compactness, and how much depends on the obstruction and the design. We will tell you honestly which targets each one excels at and where a refractor would serve you better.

Filtres

$4,499.00 USD - $4,499.00 USD
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Celestron Tube optique RASA 11" V2 - Queue d'aronde CGE

Astrographe Rowe-Ackermann Schmidt de 279mm (11") Rapport focal extrêmement rapide de f/2.2 Focale de 620mm pour l'imagerie grand champ Cercle ima...

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$4,499.00 USD - $4,499.00 USD
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$14,999.00 USD - $14,999.00 USD
$14,999.00 USD
$14,999.00 USD - $14,999.00 USD
$14,999.00 USD

Celestron Tube optique RASA V2 36 cm - Queue d'aronde CGE

Conception optique d'astrographe Rowe-Ackermann Schmidt de 355.6mm (14") Focale ultra-rapide de 790mm à un rapport focal de f/2.2 Couvre un cercle...

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$14,999.00 USD - $14,999.00 USD
$14,999.00 USD
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$14,999.00 USD
$2,199.00 USD - $2,199.00 USD
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$2,199.00 USD

Celestron Tube optique RASA 8”

Astrographe Rowe-Ackermann Schmidt de 203mm (8") Système optique incroyablement rapide à f/2.0 Focale de 400mm pour des vues grand champ Cercle im...

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$2,199.00 USD - $2,199.00 USD
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$2,199.00 USD
$3,599.00 USD - $3,599.00 USD
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$3,599.00 USD

Celestron Télescope SCT Advanced VX 11"

Tube optique Schmidt-Cassegrain de 11" (280mm) Focale de 2800mm, rapport focal f/10 Monture équatoriale allemande informatisée Advanced VX Capacit...

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$3,599.00 USD - $3,599.00 USD
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$3,599.00 USD
$1,699.00 USD - $1,699.00 USD
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$1,699.00 USD

Celestron Télescope SCT Advanced VX 6"

Tube optique Schmidt-Cassegrain de 150mm (6") Focale de 1500mm, rapport focal f/10 Monture équatoriale allemande informatisée Advanced VX Capacité...

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$1,699.00 USD - $1,699.00 USD
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$2,599.00 USD - $2,599.00 USD
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Celestron Télescope Maksutov-Cassegrain Advanced VX 700

Tube optique Maksutov-Cassegrain de 180mm (7.08") Focale de 2700mm à f/15 Monture équatoriale GoTo informatisée Advanced VX Capacité de charge de ...

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$2,599.00 USD - $2,599.00 USD
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Celestron Télescope Advanced VX 8" EdgeHD

Optique Schmidt-Cassegrain aplanétique EdgeHD de 8" (203.2mm) Focale de 2032mm à f/10 Cercle image plat de 42mm de diamètre corrigé de la coma et ...

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$2,599.00 USD - $2,599.00 USD
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$2,599.00 USD
$2,199.00 USD - $2,199.00 USD
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$2,199.00 USD - $2,199.00 USD
$2,199.00 USD

Celestron Télescope SCT Advanced VX 8"

Tube optique Schmidt-Cassegrain de 8" (203.2mm) Focale de 2032mm à f/10 Monture équatoriale allemande informatisée Advanced VX Capacité de charge ...

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$2,199.00 USD - $2,199.00 USD
$2,199.00 USD
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$2,199.00 USD
$2,899.00 USD - $2,899.00 USD
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$2,899.00 USD

Celestron Télescope Advanced VX 800 RASA

Astrographe Rowe-Ackermann Schmidt de 203mm (8") Système optique ultra-rapide à f/2.0 avec une focale de 400mm Monture équatoriale allemande infor...

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$2,899.00 USD - $2,899.00 USD
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$3,799.00 USD - $3,799.00 USD
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$3,799.00 USD

Celestron Télescope Advanced VX 9.25" EdgeHD

Optique aplanétique à champ plat EdgeHD de 9.25" (235mm) Focale de 2350mm à f/10 Cercle image de 42mm pour grands capteurs Monture équatoriale GoT...

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$3,799.00 USD - $3,799.00 USD
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$2,799.00 USD

Celestron Télescope SCT Advanced VX 9.25"

Tube optique Schmidt-Cassegrain de 9.25" (235mm) Focale de 2350mm à f/10 Monture équatoriale allemande informatisée Advanced VX Capacité de charge...

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$2,799.00 USD - $2,799.00 USD
$2,799.00 USD
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$2,399.00 USD - $2,399.00 USD
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$2,399.00 USD

Celestron Astrographe Advanced VX RASA 6"

Astrographe Rowe-Ackermann Schmidt de 152mm (5.98") Rapport focal ultra-rapide de f/2.2 avec une focale de 335mm Monture équatoriale allemande inf...

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$2,399.00 USD - $2,399.00 USD
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$579.95 USD - $579.95 USD
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$579.95 USD

Celestron Télescope Maksutov-Cassegrain Astro Fi 102mm

Tube optique Maksutov-Cassegrain de 102mm (4.02") Focale de 1325mm et rapport focal de f/13 WiFi intégré pour un contrôle complet depuis un smartp...

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$579.95 USD - $579.95 USD
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$3,300.00 USD - $3,300.00 USD
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$3,300.00 USD

Celestron Tube optique C11 - Queue d'aronde CGE

Tube optique Schmidt-Cassegrain de 279.4mm (11") Focale de 2800mm, rapport focal f/10 Résolution limite de Dawes de 0.42 seconde d'arc Traitements...

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$3,300.00 USD - $3,300.00 USD
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$6,800.00 USD - $6,800.00 USD
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$6,800.00 USD

Celestron Tube optique C14 - Queue d'aronde CGE

Tube optique Schmidt-Cassegrain de 355.5mm (14") Focale de 3910mm à f/11 Résolution limite de Dawes de 0.33 seconde d'arc Pouvoir collecteur de 25...

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$6,800.00 USD - $6,800.00 USD
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$6,800.00 USD
$880.00 USD - $880.00 USD
$880.00 USD
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$880.00 USD

Celestron Tube optique C6 - Queue d'aronde CG-5

Tube optique Schmidt-Cassegrain de 150mm (6") Focale de 1500mm (f/10) Traitements optiques StarBright XLT Poids du tube optique : 10 lbs (4.54 kg)...

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$880.00 USD - $880.00 USD
$880.00 USD
$880.00 USD - $880.00 USD
$880.00 USD
$1,400.00 USD - $1,400.00 USD
$1,400.00 USD
$1,400.00 USD - $1,400.00 USD
$1,400.00 USD

Celestron Tube optique C8 - Queue d'aronde CGE

Tube optique Schmidt-Cassegrain de 203.2mm (8") Focale de 2032mm, rapport focal f/10 Traitements optiques StarBright XLT Compatible Fastar pour l'...

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$1,400.00 USD - $1,400.00 USD
$1,400.00 USD
$1,400.00 USD - $1,400.00 USD
$1,400.00 USD
$2,000.00 USD - $2,000.00 USD
$2,000.00 USD
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$2,000.00 USD

Celestron Tube optique C9.25 - Queue d'aronde CGE

Tube optique Schmidt-Cassegrain de 235mm (9.25") Focale de 2350mm (f/10) Traitements optiques StarBright XLT Résolution de Dawes de 0.49 seconde d...

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$2,000.00 USD - $2,000.00 USD
$2,000.00 USD
$2,000.00 USD - $2,000.00 USD
$2,000.00 USD
$5,299.00 USD - $5,299.00 USD
$5,299.00 USD
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$5,299.00 USD

Celestron Télescope CGEM II 1100 EdgeHD

Système optique EdgeHD aplanétique à champ plat de 11" (279.4mm) Focale de 2800mm à f/10 natif Cercle image à champ plat de 42mm Monture CGEM II d...

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$5,299.00 USD - $5,299.00 USD
$5,299.00 USD
$5,299.00 USD - $5,299.00 USD
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$4,299.00 USD - $4,299.00 USD
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$4,299.00 USD

Celestron CGEM II 1100 SCT

Tube optique Schmidt-Cassegrain de 11 pouces (279.4mm) Capacité de charge de 40 lb (18 kg) Monture équatoriale informatisée CGEM II Traitements op...

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$4,299.00 USD - $4,299.00 USD
$4,299.00 USD
$4,299.00 USD - $4,299.00 USD
$4,299.00 USD
$3,299.00 USD - $3,299.00 USD
$3,299.00 USD
$3,299.00 USD - $3,299.00 USD
$3,299.00 USD

Celestron Télescope Maksutov-Cassegrain CGEM II 700

Tube optique Maksutov-Cassegrain de 180mm (7.08") Focale de 2700mm (f/15) Traitements optiques StarBright XLT Monture équatoriale informatisée CGE...

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$3,299.00 USD - $3,299.00 USD
$3,299.00 USD
$3,299.00 USD - $3,299.00 USD
$3,299.00 USD
$3,199.00 USD - $3,199.00 USD
$3,199.00 USD
$3,199.00 USD - $3,199.00 USD
$3,199.00 USD

Celestron Télescope CGEM II 800 EdgeHD

Optique EdgeHD aplanétique à champ plat de 8 pouces (203.2mm) Focale de 2032mm à f/10 Cercle image de 42mm, optimisé pour les 28mm centraux (APS-C...

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$3,199.00 USD - $3,199.00 USD
$3,199.00 USD
$3,199.00 USD - $3,199.00 USD
$3,199.00 USD
$3,599.00 USD - $3,599.00 USD
$3,599.00 USD
$3,599.00 USD - $3,599.00 USD
$3,599.00 USD

Celestron Télescope CGEM II 800 RASA

Astrographe Rowe-Ackermann Schmidt f/2.0 de 203mm (8") Focale de 400mm pour des champs du ciel profond ultra-larges Monture CGEM II d'une capacité...

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$3,599.00 USD - $3,599.00 USD
$3,599.00 USD
$3,599.00 USD - $3,599.00 USD
$3,599.00 USD
$2,899.00 USD - $2,899.00 USD
$2,899.00 USD
$2,899.00 USD - $2,899.00 USD
$2,899.00 USD

Celestron CGEM II 800 SCT

Tube optique Schmidt-Cassegrain de 203.2mm (8") Rapport focal f/10 avec traitements StarBright XLT Monture équatoriale CGEM II d'une capacité de c...

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$2,899.00 USD - $2,899.00 USD
$2,899.00 USD
$2,899.00 USD - $2,899.00 USD
$2,899.00 USD

Schmidt-Cassegrain, Maksutov and Hybrid Designs

All catadioptrics combine a mirror with a corrector lens to fold the light path. The differences between them come down to the corrector, the obstruction size and how quickly the tube cools.

  • Schmidt-Cassegrains: A thin aspheric corrector plate with a moderate central obstruction, typically f/10. The most versatile long-focal-length design and the best supported by accessories.
  • Maksutov-Cassegrains: A thick meniscus corrector giving very high contrast and sharp planetary images, usually f/12 to f/15. Slower to cool because of the corrector's thermal mass.
  • Maksutov-Newtonians: A Maksutov corrector on a Newtonian layout, giving refractor-like contrast at a faster focal ratio with a small obstruction.
  • Advanced coma-free and hybrid designs: Modified Cassegrains that eliminate off-axis coma, aimed at imaging with large sensors at long focal length.
  • Reducer-correctors: Typically 0.63x for SCTs, turning f/10 into a much more practical f/6.3 for imaging and widening the field considerably.
  • Mirror shift and focus: Moving-mirror focusing can shift the image slightly; an external focuser and mirror lock make long-exposure imaging far more repeatable.

Why Choose David Astro for Schmidt-Cassegrains and Maksutovs

Long focal length is unforgiving of mount error, seeing and thermal management. Buying one well means planning for all three.

  • Mount sized for the focal length: At 2000 mm, guiding tolerances are several times tighter than at 500 mm. We size the mount to the focal length rather than to the tube weight alone.
  • Cooling advice for Canadian conditions: A closed tube taking an hour to reach ambient will show soft planetary detail all evening. We discuss cooling fans and setup timing before you buy.
  • Back-focus and reducer spacing: SCT reducers have specific spacing requirements, and we supply the adapter list to hit them exactly.
  • Authorized dealer: Full manufacturer warranty and verified authenticity, with service handled domestically in Canada.
  • Ships from Canada: No duties or brokerage fees for Canadian buyers on heavy optics.

Schmidt-Cassegrains and Maksutovs in Canada — Frequently Asked Questions

SCT or Maksutov for planets?
A Maksutov usually gives slightly higher contrast at the same aperture because of its smaller obstruction, but is slower to cool and available in smaller apertures. An SCT gives more aperture for the money and more accessory flexibility.
How long do these take to cool?
An 8 inch SCT typically needs 45 to 60 minutes from a warm house to a Canadian winter night; a Maksutov of the same size can take longer. A rear cooling fan reduces this substantially.
Can I image deep sky with an SCT?
Yes, with a 0.63x reducer and a capable mount. Native f/10 is demanding for deep sky; reduced to f/6.3 it becomes practical for galaxies and planetary nebulae, though guiding must still be excellent.
What is mirror shift and does it matter?
The primary mirror moves on a baffle tube to focus, and can tilt slightly, shifting the image as you focus. For imaging, use a mirror lock and an external focuser to eliminate it.

Planning a long focal length setup?

Tell us your targets and mount and we will match the optic and reducer. Ships from Canada with setup support.