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Refractors

Réfracteurs

Refractors earn their following through consistency. A sealed lens system holds collimation indefinitely, cools quickly, gives high-contrast views without a central obstruction, and — in modern apochromatic form — produces the clean, round stars that make wide-field astrophotography look effortless. David Astro carries refractors in Canada, from compact 50 mm travel astrographs to large apochromatic triplets, shipping from Canadian stock.

We image with refractors under Canadian skies and can speak to the practical differences between doublets and triplets, and between glass types, in terms of what actually shows in a finished image rather than what appears on a specification sheet.

Filtres

CA$1,679.00 - CA$1,679.00
CA$1,679.00
CA$1,679.00 - CA$1,679.00
CA$1,679.00

Askar 103APO f/6.8 Triplet

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Caractéristique de conception du tube d'objectif amovible Ouverture de 103 mm, distance focale de 700 mm et rapports focaux natifs de 6,8 A...

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CA$1,679.00 - CA$1,679.00
CA$1,679.00
CA$1,679.00 - CA$1,679.00
CA$1,679.00
CA$3,219.00 - CA$3,219.00
CA$3,219.00
CA$3,219.00 - CA$3,219.00
CA$3,219.00

Askar 107PHQ f/7 Quadruplet APO

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1 en stock

En tant que premier astrographe Flatfield à rapport focal long d'Askar, 107PHQ est né avec une mission spéciale : que vous débutiez en astrophotogr...

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CA$3,219.00 - CA$3,219.00
CA$3,219.00
CA$3,219.00 - CA$3,219.00
CA$3,219.00
CA$2,379.00 - CA$2,379.00
CA$2,379.00
CA$2,379.00 - CA$2,379.00
CA$2,379.00

Askar 120APO f/7 Triplet

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120mm Aperture Triplet Air-Spaced APO Objective Includes one ED Glass Element for Superb Color Correction 840mm Focal Length at a Native f/7 Focal...

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CA$2,379.00 - CA$2,379.00
CA$2,379.00
CA$2,379.00 - CA$2,379.00
CA$2,379.00
CA$4,899.00 - CA$4,899.00
CA$4,899.00
CA$4,899.00 - CA$4,899.00
CA$4,899.00

Askar 130PHQ f/7 Quadruplet APO

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130PHQ est un astrographe à champ plat à longue focale nouvellement lancé après 107PHQ. Au lieu d'acheter des aplatisseurs supplémentaires, de calc...

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CA$4,899.00 - CA$4,899.00
CA$4,899.00
CA$4,899.00 - CA$4,899.00
CA$4,899.00
Askar 131F Flat-Field APO Refractor
CA$2,799.00 - CA$2,799.00
CA$2,799.00
CA$2,799.00 - CA$2,799.00
CA$2,799.00

Askar 131F Flat-Field APO Refractor

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131mm Aperture f/7.5 Focal Ratio Quadruplet Air-Spaced APO Optical Design Includes one ED Glass Element 44mm Full-Frame Image Circle Integrated Fi...

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CA$2,799.00 - CA$2,799.00
CA$2,799.00
CA$2,799.00 - CA$2,799.00
CA$2,799.00
CA$3,499.00 - CA$3,499.00
CA$3,499.00
CA$3,499.00 - CA$3,499.00
CA$3,499.00

Askar 140APO f/7 Triplet

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2 en stock

Que vous soyez astronome amateur ou astrophotographe professionnel, l'Askar 140APO vous offrira une expérience utilisateur de haute qualité et vou...

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CA$3,499.00 - CA$3,499.00
CA$3,499.00
CA$3,499.00 - CA$3,499.00
CA$3,499.00
Askar 151PHQ f/7 Quadruplet Astrograph
CA$6,299.00 - CA$6,299.00
CA$6,299.00
CA$6,299.00 - CA$6,299.00
CA$6,299.00

Askar 151PHQ f/7 Quadruplet Astrograph

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151mm Aperture Quadruplet APO Optics 1057mm Focal Length at f/7 Integrated Flattener for a 60mm Image Circle Includes Two ED Glass Elements for Co...

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CA$6,299.00 - CA$6,299.00
CA$6,299.00
CA$6,299.00 - CA$6,299.00
CA$6,299.00
CA$5,383.00 - CA$5,383.00
CA$5,383.00
CA$5,383.00 - CA$5,383.00
CA$5,383.00

Askar 160APO f/7 Triplet

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160mm Aperture Triplet Air-Spaced APO Objective 1120mm Focal Length at f/7 Includes One ED Glass Element for Color Correction Retractable Dew Shie...

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CA$5,383.00 - CA$5,383.00
CA$5,383.00
CA$5,383.00 - CA$5,383.00
CA$5,383.00
CA$7,391.00 - CA$7,391.00
CA$7,391.00
CA$7,391.00 - CA$7,391.00
CA$7,391.00

Askar 185APO f/7 Triplet

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1 en stock

En tant que réfracteur à grande ouverture, Askar 185APO comble le poste vacant sur le marché, perpétue la haute qualité et la rentabilité des téle...

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CA$7,391.00 - CA$7,391.00
CA$7,391.00
CA$7,391.00 - CA$7,391.00
CA$7,391.00
Askar 203APO f/7 Triplet APO Refractor
CA$12,011.00 - CA$12,011.00
CA$12,011.00
CA$12,011.00 - CA$12,011.00
CA$12,011.00

Askar 203APO f/7 Triplet APO Refractor

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203mm Aperture Triplet Air-Spaced APO Objective 1421mm Focal Length at f/7 Includes one ED (Extra-Low Dispersion) Glass Element Retractable Tube D...

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CA$12,011.00 - CA$12,011.00
CA$12,011.00
CA$12,011.00 - CA$12,011.00
CA$12,011.00
CA$419.00 - CA$419.00
CA$419.00
CA$419.00 - CA$419.00
CA$419.00

Askar 50P f/3.8 Quadruplet APO Telescope

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5 en stock

50mm Aperture Quadruplet APO Optics Ultra-Fast f/3.8 Focal Ratio 190mm Focal Length Natively Flat Field for APS-C Sensors Standard 55mm Back Focus...

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CA$419.00 - CA$419.00
CA$419.00
CA$419.00 - CA$419.00
CA$419.00
Askar 60F Flat-Field Astrograph
CA$699.00 - CA$699.00
CA$699.00
CA$699.00 - CA$699.00
CA$699.00

Askar 60F Flat-Field Astrograph

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1 en stock

60mm Aperture Quadruplet APO Optics 408mm Focal Length f/6.8 Native Focal Ratio 44mm Full-Frame Image Circle Integrated Field Flattener 2.86kg Gro...

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CA$699.00 - CA$699.00
CA$699.00
CA$699.00 - CA$699.00
CA$699.00
Askar 65PHQ f/6.4 Quintuplet Flat-Field Astrograph
CA$1,259.00 - CA$1,259.00
CA$1,259.00
CA$1,259.00 - CA$1,259.00
CA$1,259.00

Askar 65PHQ f/6.4 Quintuplet Flat-Field Astrograph

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65mm Aperture Quintuplet APO Optical Design 416mm Focal Length at f/6.4 Built-in Field Flattener with 44mm Image Circle 2.8kg Total Weight Includi...

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CA$1,259.00 - CA$1,259.00
CA$1,259.00
CA$1,259.00 - CA$1,259.00
CA$1,259.00
CA$923.00 - CA$923.00
CA$923.00
CA$923.00 - CA$923.00
CA$923.00

Askar 71F Quadruplet champ plat APO f/6.9

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Ouverture de 71 mm, réfracteur apochromatique quadruplet à rapport focal f/6,9 Conception à champ plat optimisée pour l'astrophotographi...

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CA$923.00 - CA$923.00
CA$923.00
CA$923.00 - CA$923.00
CA$923.00
CA$559.00 - CA$559.00
CA$559.00
CA$559.00 - CA$559.00
CA$559.00

Askar 80ED f/7 Doublet

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1 en stock

560mm Focal Length f/7 Focal Ratio Triplet Objective with ED Glass APS-C Corrected Image Circle 55mm Back Focus 0.42kg Weight Description FAQ S...

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CA$559.00 - CA$559.00
CA$559.00
CA$559.00 - CA$559.00
CA$559.00
CA$2,099.00 - CA$2,099.00
CA$2,099.00
CA$2,099.00 - CA$2,099.00
CA$2,099.00

Askar 80PHQ f/7 Quadruplet APO

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Ouverture de 80 mm, réfracteur apochromatique quadruplet à rapport focal f/7 Conçu pour l'astrophotographie et l'observation visuelle de ...

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CA$2,099.00 - CA$2,099.00
CA$2,099.00
CA$2,099.00 - CA$2,099.00
CA$2,099.00
Askar 91F Flat-Field Astrograph
CA$1,399.00 - CA$1,399.00
CA$1,399.00
CA$1,399.00 - CA$1,399.00
CA$1,399.00

Askar 91F Flat-Field Astrograph

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91mm Aperture Quadruplet APO Optics 609mm Focal Length at f/6.7 44mm Full-Frame Corrected Image Circle Integrated Field Flattener Design 3.92kg Ne...

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CA$1,399.00 - CA$1,399.00
CA$1,399.00
CA$1,399.00 - CA$1,399.00
CA$1,399.00
CA$461.00 - CA$461.00
CA$461.00
CA$461.00 - CA$461.00
CA$461.00

Objectif Askar FMA135 135mm f/4.5 APO

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1 en stock

Le tout nouveau début d'année 2021 voit l'avènement de notre astrographe FMA135 qui a hérité de la qualité constante, de la compacité et de la poly...

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CA$461.00 - CA$461.00
CA$461.00
CA$461.00 - CA$461.00
CA$461.00
CA$615.00 - CA$615.00
CA$615.00
CA$615.00 - CA$615.00
CA$615.00

Askar FMA180 Pro 180mm f/4.5 APO Full Frame Lens

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Pour offrir aux clients plus d'options, Askar a lancé le nouveau FMA180 pro. Le FMA180 pro est similaire au FMA180 en termes de conception opt...

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CA$615.00 - CA$615.00
CA$615.00
CA$615.00 - CA$615.00
CA$615.00
CA$1,329.00 - CA$1,329.00
CA$1,329.00
CA$1,329.00 - CA$1,329.00
CA$1,329.00

Askar FRA300 Pro 60 mm f/5 Quintuplet APO

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60 mm f/5 Quintuplet APO Cercle d'image à champ plat de 44 mm Distance focale de 300 mm Porte-oculaire à crémaillère et pigno...

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CA$1,329.00 - CA$1,329.00
CA$1,329.00
CA$1,329.00 - CA$1,329.00
CA$1,329.00
CA$1,679.00 - CA$1,679.00
CA$1,679.00
CA$1,679.00 - CA$1,679.00
CA$1,679.00

Askar FRA400 72mm f/5.6 Quintuplet APO

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72 mm f/5,6 Quintuplet APO Cercle d'image à champ plat de 44 mm Distance focale de 400 mm Porte-oculaire à crémaillère et pignon 3" avec ro...

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CA$1,679.00 - CA$1,679.00
CA$1,679.00
CA$1,679.00 - CA$1,679.00
CA$1,679.00
CA$1,253.00 - CA$1,253.00
CA$1,253.00
CA$1,253.00 - CA$1,253.00
CA$1,253.00

Askar FRA400C 72mm f/5.6 Quintuplet APO

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72mm Aperture Quintuplet APO Optics 400mm Focal Length at f/5.6 Covers a 44mm Full-Frame Image Circle Integrated 17-Blade Aperture (f/5.6-f/22) 2....

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CA$1,253.00 - CA$1,253.00
CA$1,253.00
CA$1,253.00 - CA$1,253.00
CA$1,253.00
CA$2,799.00 - CA$2,799.00
CA$2,799.00
CA$2,799.00 - CA$2,799.00
CA$2,799.00

Askar FRA500 90mm f/5.6 Quintuplet APO

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Compact et portable Imagerie de haute qualité Mise au point de précision Conception élégante Description Caractéristiques ...

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CA$2,799.00 - CA$2,799.00
CA$2,799.00
CA$2,799.00 - CA$2,799.00
CA$2,799.00
CA$3,639.00 - CA$3,639.00
CA$3,639.00
CA$3,639.00 - CA$3,639.00
CA$3,639.00

Askar FRA600 108mm f/5.6 Quintuplet APO

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Aujourd'hui, Sharpstar annonce le plus récent ajout à sa série Askar FRA, l'Askar FRA600/5.6. Après les excellentes performances optiques de son...

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CA$3,639.00 - CA$3,639.00
CA$3,639.00
CA$3,639.00 - CA$3,639.00
CA$3,639.00

Doublets, Triplets and Glass Types

The purpose of an apochromatic design is to bring three wavelengths to a common focus, eliminating the violet halo that achromatic refractors show on bright stars. How well it does that depends on the glass and the number of elements.

  • ED doublets: Two elements with one extra-low dispersion element. Lighter, less expensive, and excellent for imaging, with a small residual colour that is rarely visible in processed images.
  • Apochromatic triplets: Three elements giving near-complete colour correction, preferred for high-contrast visual observing and for imaging bright stars without halos. Heavier and slower to cool.
  • Petzval designs: Four-element optics with the field correction built in, so no separate flattener is needed and back-focus is fixed by the manufacturer — the simplest path to flat fields.
  • Achromatic refractors: Two-element crown and flint designs, excellent value for lunar, planetary and general visual use where some colour fringing on bright objects is acceptable.
  • Focal ratio: Fast refractors around f/5 give wide fields and short exposures; f/7 and slower give more image scale and are more forgiving of corrector spacing.
  • Matched correctors: Most refractors need a flattener or reducer designed for that specific model, spaced to its exact back-focus.

Why Choose David Astro for Refractors

A refractor is usually bought as the centre of an imaging system, so it should be specified alongside the mount and camera rather than on its own.

  • Corrector matched at the point of sale: We identify the flattener or reducer designed for your specific tube and supply the spacers to hit its back-focus exactly.
  • Focuser load assessed: We check that the stock focuser will carry your intended camera train without slip, and recommend an upgrade only when it genuinely will not.
  • Authorized dealer: Full manufacturer warranty and verified authenticity, with service handled inside Canada.
  • Ships from Canadian stock: No duties or brokerage fees for Canadian buyers, and no extra border handling for a precision optic.
  • Support after first light: Help with spacing, tilt and star shape diagnosis once the telescope is on the sky.

Refractors in Canada — Frequently Asked Questions

Doublet or triplet for imaging?
A good ED doublet is entirely sufficient for most deep-sky imaging and is lighter on the mount. A triplet shows its advantage on bright stars and in high-contrast visual use, at meaningful extra weight and cost.
Do I need a field flattener?
For imaging with anything larger than a small sensor, yes — a two-element refractor has a curved focal plane and corners will show elongated stars without one. Petzval designs have it built in.
How long does a refractor take to cool?
A small doublet is usable almost immediately. A large triplet can take 45 minutes or more to stabilize in Canadian winter conditions, and imaging before it does will show soft, bloated stars.
Is a small refractor enough for deep sky?
Yes, given integration time. A 60 to 80 mm apochromat on a good mount produces excellent wide-field images; total exposure time substitutes for aperture in imaging in a way it cannot for visual work.

Specifying a refractor?

Tell us your mount, camera and targets and we will match the tube and its corrector. Canadian stock, no surprise duties.