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Closed October 10–12 for Thanksgiving weekend
Closed October 10–12 for Thanksgiving weekend
Refractors

Refractors

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.

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SVBONY SV502 Astronomy Telescope for Kids
CA$63.00 - CA$63.00
CA$63.00
CA$63.00 - CA$63.00
CA$63.00

SVBONY SV502 Astronomy Telescope for Kids

SV-F9350A

50mm Refractor Telescope 360mm Focal Length (f/7.2) Includes K20mm Eyepiece 5x20 Optical Viewfinder 45-Degree Correct-Image Prism for Upright View...

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CA$63.00 - CA$63.00
CA$63.00
CA$63.00 - CA$63.00
CA$63.00
SVBONY SV503 102mm f/7 ED Doublet Refractor OTA
CA$735.00 - CA$735.00
CA$735.00
CA$735.00 - CA$735.00
CA$735.00

SVBONY SV503 102mm f/7 ED Doublet Refractor Telescope OTA

SV-F9359D

102mm Aperture ED Doublet Refractor 714mm Focal Length (f/7) S-FPL51 Extra-Low Dispersion Glass 1:10 Dual-Speed Rack & Pinion Focuser 101.9mm ...

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CA$735.00 - CA$735.00
CA$735.00
CA$735.00 - CA$735.00
CA$735.00
SVBONY SV503 70mm f/6.78 Quadruplet ED Flatfield Refractor Telescope OTA
SVBONY SV503 70mm f/6.78 Quadruplet ED Flatfield Refractor Telescope OTA
CA$503.00 - CA$503.00
CA$503.00
CA$503.00 - CA$503.00
CA$503.00

SVBONY SV503 70mm f/6.78 Quadruplet ED Flatfield Refractor Telescope OTA

SV-F9359E
1 in stock

70mm Aperture Quadruplet Astrograph 474mm Focal Length (f/6.78) 32mm Corrected Flat-Field Image Circle 2.5" Rack-and-Pinion Focuser 127.5mm Workin...

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CA$503.00 - CA$503.00
CA$503.00
CA$503.00 - CA$503.00
CA$503.00
CA$580.00 - CA$580.00
CA$580.00
CA$580.00 - CA$580.00
CA$580.00

SVBONY SV503 ED 80mm F7 Doublet

SV-F9359B

1.Rugged housing prevents damage; 2.Sliding graceful and soft dual-speed focuser; 3.Ed glass (S-FPL51) can produce very beautiful and clear images...

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CA$580.00 - CA$580.00
CA$580.00
CA$580.00 - CA$580.00
CA$580.00
SVBONY SV520 Astronomy Telescope Complete Kit for Beginners
SVBONY SV520 Astronomy Telescope Complete Kit for Beginners
CA$280.00 - CA$280.00
CA$280.00
CA$280.00 - CA$280.00
CA$280.00

SVBONY SV520 Astronomy Telescope Complete Kit for Beginners

SV-W9302A-W9195A-W9195B

90mm Objective Aperture f/8.9 Focal Ratio Alt-Azimuth Mount with Worm Gear Slow-Motion Controls Includes 3X Barlow Lens 5x24 Optical Finder Scope ...

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CA$280.00 - CA$280.00
CA$280.00
CA$280.00 - CA$280.00
CA$280.00
SVBONY Petzval Refractor Astrograph Lens | SVBONY SV545
CA$560.00 - CA$560.00
CA$560.00
CA$560.00 - CA$560.00
CA$560.00

SVBONY SV545 45mm f/4.5 203mm Petzval Refractor Astrograph Lens

SV-W9317B

45mm Aperture 203mm Focal Length (f/4.5) 5-Element Petzval Optical Design Native Flat-Field Astrograph Helical Focuser with 360º Rotator M48x0.75 ...

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CA$560.00 - CA$560.00
CA$560.00
CA$560.00 - CA$560.00
CA$560.00
CA$1,903.00 - CA$1,903.00
CA$1,903.00
CA$1,903.00 - CA$1,903.00
CA$1,903.00

SVBONY SV550 122mm APO Refractor Telescope OTA

SV-F9381C

122mm Aperture f/7 Focal Ratio 854mm Focal Length Apochromatic Triplet Lens with FPL-51 ED Glass Super Multi-Coated (SMC) Optics 6440g Net Weight ...

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CA$1,903.00 - CA$1,903.00
CA$1,903.00
CA$1,903.00 - CA$1,903.00
CA$1,903.00
SVBONY SV550 80mm f/6 APO Triplet Refractor Telescope OTA
SVBONY SV550 80mm f/6 APO Triplet Refractor Telescope OTA
CA$783.00 - CA$783.00
CA$783.00
CA$783.00 - CA$783.00
CA$783.00

SVBONY SV550 80mm f/6 APO Triplet Refractor Telescope OTA

SV-F9381A
1 in stock

80mm Aperture Apochromatic Triplet Refractor 480mm Focal Length Fast f/6 Focal Ratio FPL51 ED Glass Element for Color Correction Resolving Power o...

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CA$783.00 - CA$783.00
CA$783.00
CA$783.00 - CA$783.00
CA$783.00
SVBONY SV555 54mm f/4.5 Petzval APO Astrograph Lens
SVBONY SV555 54mm f/4.5 Petzval APO Astrograph Lens
CA$714.00 - CA$714.00
CA$714.00
CA$714.00 - CA$714.00
CA$714.00

SVBONY SV555 54mm f/4.5 Petzval APO Astrograph Lens

SV-F9395A
1 in stock

54mm Aperture / 243mm Focal Length (f/4.5) 5-Element Petzval APO Optical Design 44mm Full-Frame Image Circle Variable f/4.5 to f/22 Aperture Ring ...

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CA$714.00 - CA$714.00
CA$714.00
CA$714.00 - CA$714.00
CA$714.00
Tele Vue TV-60 OTA 2
Tele Vue TV-60 OTA 1
CA$1,214.00 - CA$1,214.00
CA$1,214.00
CA$1,214.00 - CA$1,214.00
CA$1,214.00

Tele Vue TV-60 OTA

TV-TVO-2460

Aperture: 60mm Focal Length: 360mm Focal Ratio: f/6 Optical Design: APO Doublet (2 elements / 1 group) Focuser: 1.25" Helical Weight: 3 lbs (OTA) ...

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CA$1,214.00 - CA$1,214.00
CA$1,214.00
CA$1,214.00 - CA$1,214.00
CA$1,214.00
Tele Vue TV-76 OTA - Green 1
CA$2,428.00 - CA$2,428.00
CA$2,428.00
CA$2,428.00 - CA$2,428.00
CA$2,428.00

Tele Vue TV-76 OTA - Green

TV-GXO-3065

Aperture: 76mm Focal Length: 480mm Focal Ratio: f/6.3 Optical Design: APO Doublet (2 elements / 1 group) Focuser: 2-inch Focusmate Dual-Speed Rack...

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CA$2,428.00 - CA$2,428.00
CA$2,428.00
CA$2,428.00 - CA$2,428.00
CA$2,428.00
Tele Vue TV-76 OTA - White 1
CA$2,428.00 - CA$2,428.00
CA$2,428.00
CA$2,428.00 - CA$2,428.00
CA$2,428.00

Tele Vue TV-76 OTA - White

TV-WXO-3065

Aperture: 76mm Focal Length: 480mm Focal Ratio: f/6.3 Optical Design: APO Doublet (2 elements / 1 group) Focuser: 2-inch Focusmate Dual-Speed Rack...

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CA$2,428.00 - CA$2,428.00
CA$2,428.00
CA$2,428.00 - CA$2,428.00
CA$2,428.00
Tele Vue TV-85 OTA - Green 1
CA$3,034.00 - CA$3,034.00
CA$3,034.00
CA$3,034.00 - CA$3,034.00
CA$3,034.00

Tele Vue TV-85 OTA - Green

TV-GXO-3372

Aperture: 85mm Focal Length: 600mm Focal Ratio: f/7 Optical Design: APO Doublet (2 elements / 1 group) Focuser: 2-inch Focusmate Dual-Speed Rack a...

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CA$3,034.00 - CA$3,034.00
CA$3,034.00
CA$3,034.00 - CA$3,034.00
CA$3,034.00
Tele Vue TV-85 OTA - White 1
CA$3,034.00 - CA$3,034.00
CA$3,034.00
CA$3,034.00 - CA$3,034.00
CA$3,034.00

Tele Vue TV-85 OTA - White

TV-WXO-3372

Aperture: 85mm Focal Length: 600mm Focal Ratio: f/7 Optical Design: Apochromatic (APO) Doublet Focuser: 2-inch, 10:1 Dual-Speed Rack-and-Pinion We...

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CA$3,034.00 - CA$3,034.00
CA$3,034.00
CA$3,034.00 - CA$3,034.00
CA$3,034.00
Tele Vue TV-NP101is OTA 1
CA$5,974.00 - CA$5,974.00
CA$5,974.00
CA$5,974.00 - CA$5,974.00
CA$5,974.00

Tele Vue TV-NP101is OTA

TV-NPI-4057

Aperture: 101mm Focal Length: 540mm Focal Ratio: f/5.4 Optical Design: APO Nagler-Petzval (4 elements / 2 groups) Focuser: 2.4" Focusmate Dual-Spe...

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CA$5,974.00 - CA$5,974.00
CA$5,974.00
CA$5,974.00 - CA$5,974.00
CA$5,974.00
Tele Vue TV-NP127is OTA 1
CA$10,322.00 - CA$10,322.00
CA$10,322.00
CA$10,322.00 - CA$10,322.00
CA$10,322.00

Tele Vue TV-NP127is OTA

TV-NPI-5054

Aperture: 127mm Focal Length: 660mm Focal Ratio: f/5.2 Optical Design: APO Nagler-Petzval (4 elements / 2 groups) Focuser: 2.4" Focusmate Dual-Spe...

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CA$10,322.00 - CA$10,322.00
CA$10,322.00
CA$10,322.00 - CA$10,322.00
CA$10,322.00
CA$3,741.00 - CA$4,137.00
CA$3,741.00 - CA$4,137.00
CA$3,741.00 - CA$4,137.00
CA$3,741.00

William Optics Cat 91 WIFD

Options available
1 variants in stock

91mm Aperture, 448mm Focal Length (f/4.9) 5-Element Advanced Petzval Optical Design 55mm Corrected Image Circle WIFD Rack & Pinion Internal Fo...

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CA$3,741.00 - CA$4,137.00
CA$3,741.00 - CA$4,137.00
CA$3,741.00 - CA$4,137.00
CA$3,741.00
CA$4,965.00 - CA$4,965.00
CA$4,965.00
CA$4,965.00 - CA$4,965.00
CA$4,965.00

William Optics Fluorostar 120

Options available

120mm Aperture FPL-53 Triplet Apochromatic Optics 3.3" Rack & Pinion Focuser Built-in Camera Angle Rotator Integrated Bahtinov Mask Descrip...

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CA$4,965.00 - CA$4,965.00
CA$4,965.00
CA$4,965.00 - CA$4,965.00
CA$4,965.00
CA$6,304.00 - CA$8,162.00
CA$6,304.00 - CA$8,162.00
CA$6,304.00 - CA$8,162.00
CA$6,304.00

William Optics Fluorostar 132

Options available

132mm Aperture, 910mm Focal Length (f/6.9) Air-Spaced Triplet Apochromatic Objective Premium FPL-53 Glass for Superior Color Correction Heavy-Duty...

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CA$6,304.00 - CA$8,162.00
CA$6,304.00 - CA$8,162.00
CA$6,304.00 - CA$8,162.00
CA$6,304.00
CA$10,653.00 - CA$12,417.00
CA$10,653.00 - CA$12,417.00
CA$10,653.00 - CA$12,417.00
CA$10,653.00

William Optics Fluorostar 156

Options available

156mm Aperture Triplet Apochromat 1217mm Focal Length (f/7.8) FPL-53 & Lanthanum Glass Elements 3.7" Rack & Pinion Focuser Thermally Stabl...

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CA$10,653.00 - CA$12,417.00
CA$10,653.00 - CA$12,417.00
CA$10,653.00 - CA$12,417.00
CA$10,653.00
CA$2,877.00 - CA$3,033.00
CA$2,877.00 - CA$3,033.00
CA$2,877.00 - CA$3,033.00
CA$2,877.00

William Optics Fluorostar 91

Options available

91mm Aperture Apochromatic Triplet FPL-53 Glass for Superior Color Correction Strehl Ratio Exceeding 0.95 3.3" Dual-Speed Rack & Pinion Focuse...

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CA$2,877.00 - CA$3,033.00
CA$2,877.00 - CA$3,033.00
CA$2,877.00 - CA$3,033.00
CA$2,877.00
CA$1,515.00 - CA$1,515.00
CA$1,515.00
CA$1,515.00 - CA$1,515.00
CA$1,515.00

William Optics Gran Turismo 71 APO Triplet

WO-A-F71GTII-RD

71mm Triplet Apochromatic Lens 419mm Focal Length at f/5.9 44mm Full-Frame Image Circle 2.5" Rack & Pinion Focuser OTA Weight: 2.95 kg (6.5 lb...

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CA$1,515.00 - CA$1,515.00
CA$1,515.00
CA$1,515.00 - CA$1,515.00
CA$1,515.00
CA$3,033.00 - CA$3,033.00
CA$3,033.00
CA$3,033.00 - CA$3,033.00
CA$3,033.00

William Optics Gran Turismo WIFD 81

Options available

81mm Aperture Triplet Apochromatic Refractor FPL-53 Ohara Glass for Superior Color Correction William Optics Internal Focusing Design (WIFD) Inclu...

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CA$3,033.00 - CA$3,033.00
CA$3,033.00
CA$3,033.00 - CA$3,033.00
CA$3,033.00
CA$1,363.00 - CA$1,363.00
CA$1,363.00
CA$1,363.00 - CA$1,363.00
CA$1,363.00

William Optics MiniCat 51 WIFD f/3.5

WO-T-C-MINI-RD
3 in stock

51mm Aperture Diameter 178mm Focal Length f/3.5 Focal Ratio 6-Element Petzval Optical Design 43.2mm Full-Frame Image Circle WIFD Rack & Pinion...

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CA$1,363.00 - CA$1,363.00
CA$1,363.00
CA$1,363.00 - CA$1,363.00
CA$1,363.00

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.