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Sales & Clearance

Astronomy sales at David Astro — current markdowns across the catalogue, including open-box units, discontinued models still fully supported, and overstock we would rather see on a telescope than on a shelf. Everything here is held in Canadian stock and carries the same warranty and support as full-price inventory.

Reduced price does not mean reduced service. We will still calculate your back-focus, confirm compatibility and support the item after the sale, exactly as we would for anything else in the catalogue.

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$2,598.00 USD - $2,998.00 USD
$2,598.00 USD
$2,468.10 USD - $2,848.10 USD
$2,468.10 USD - $2,848.10 USD
$2,468.10 USD

William Optics Cat 91 WIFD

91mm Aperture 448mm Focal Length f/4.9 Focal Ratio 5-Element Advanced Petzval Design 55mm Corrected Image Circle WIFD Rack & Pinion Internal F...

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$2,598.00 USD - $2,998.00 USD
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$2,468.10 USD
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$50.00 USD
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$50.00 USD
$47.50 USD
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$47.50 USD

William Optics Cat Mounting Ring

Solid Aluminum Construction Anodized Black Finish Description FAQ Specifications In the Box Warranty William Optics Cat Mo...

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$50.00 USD
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$50.00 USD
$47.50 USD
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$47.50 USD
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$36.00 USD - $38.00 USD
$36.00 USD
$34.20 USD - $36.10 USD
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$34.20 USD

William Optics DSD 110 Plate

Dual-Sided Dovetail Plate Design Fits Vixen-Style Saddles Fits Arca-Swiss Clamps Precision CNC-Machined Construction Durable Anodized Finish De...

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$36.00 USD - $38.00 USD
$36.00 USD
$34.20 USD - $36.10 USD
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$34.20 USD
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$45.00 USD - $48.00 USD
$45.00 USD
$42.75 USD - $45.60 USD
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$42.75 USD

William Optics DSD 210 Plate

210 mm total length for balancing flexibility Dual-profile fits both Vixen-style and Arca-Swiss clamps CNC-machined for a precise and secure fit ...

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$45.00 USD - $48.00 USD
$45.00 USD
$42.75 USD - $45.60 USD
$42.75 USD - $45.60 USD
$42.75 USD
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$51.76 USD - $58.00 USD
$51.76 USD
$49.17 USD - $55.10 USD
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$49.17 USD

William Optics DSD 245 Plate

Length: 245 mm Weight: 0.33 kg / 0.72 lbs Dovetail Compatibility: Vixen & Arca-Swiss CNC-machined construction Description FAQ Specificatio...

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$51.76 USD - $58.00 USD
$51.76 USD
$49.17 USD - $55.10 USD
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$49.17 USD
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$388.00 USD
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$369.00 USD
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$369.00 USD

William Optics Elite Drawer OAG Kit

Integrates Off-Axis Guider and Filter Drawer 37.5 mm Optical Length Supports M48, M54, and M68 Connections Magnetic M48 Filter Holder 336 g (11.85...

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$388.00 USD
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$388.00 USD
$369.00 USD
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$369.00 USD
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$34.00 USD
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$34.00 USD
$32.30 USD
$32.30 USD - $32.30 USD
$32.30 USD

William Optics Extension Bar for iOptron Skyguider Pro

Counterweight extension bar for the iOptron SkyGuider Pro Specifically designed to fit the iOptron SkyGuider Pro Description T...

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$34.00 USD
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$32.30 USD
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$32.30 USD
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$64.00 USD
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$60.80 USD

William Optics Flat4 Draw Tube Adapter for FLT (Gold) for 2012-2016 Models

Securely connects the Flat4 Field Flattener to the draw tube Designed for William Optics FLT 98, 110, 132, and 152 models Compatible with telescop...

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$64.00 USD
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$64.00 USD
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$60.80 USD

William Optics Flat4 Draw Tube Adapter for GT102, FLT 132 - Black for 3" V-Power Focuser

Connects William Optics Flat4 Flattener to Draw Tube Designed for 2017 William Optics V-Power telescopes Compatible with V-Power 102 & 132 (20...

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$64.00 USD
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$64.00 USD
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$60.80 USD

William Optics Flat4 Draw Tube Adapter for GT102, FLT 132 - Blue for 3" V-power Focuser

Connects Flat4 Flattener to the V-Power Focuser Compatible with William Optics GT102 & FLT 132 Engineered for 2017 Telescope Models Secure Thr...

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$64.00 USD
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$64.00 USD
$60.80 USD
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$788.00 USD
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$788.00 USD
$748.60 USD
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$748.60 USD

William Optics Flattener 68III

1.0x Flattener Power preserves native focal length Corrects field curvature for Full Frame sensors Designed for William Optics FLT132, GT102, and ...

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$788.00 USD
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$788.00 USD
$748.60 USD
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$748.60 USD
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$3,598.00 USD
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$3,418.10 USD
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William Optics Fluorostar 120

120mm Aperture f/6.5 Focal Ratio FPL-53 Apochromatic Triplet Optics 3.3-inch Dual-Speed Rack & Pinion Focuser Image Circle >43mm Integrated...

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$3,598.00 USD
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$3,418.10 USD
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$4,378.00 USD - $5,668.00 USD
$4,378.00 USD
$4,159.10 USD - $5,384.60 USD
$4,159.10 USD - $5,384.60 USD
$4,159.10 USD

William Optics Fluorostar 132

132mm Aperture 910mm Focal Length f/6.9 Focal Ratio FPL-53 Air-Spaced Apochromatic Triplet Objective 3.7" Rack & Pinion Focuser with...

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$4,378.00 USD - $5,668.00 USD
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$4,159.10 USD - $5,384.60 USD
$4,159.10 USD - $5,384.60 USD
$4,159.10 USD
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$7,398.00 USD - $8,998.00 USD
$7,398.00 USD
$7,028.10 USD - $8,548.10 USD
$7,028.10 USD - $8,548.10 USD
$7,028.10 USD

William Optics Fluorostar 156

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

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$7,398.00 USD - $8,998.00 USD
$7,398.00 USD
$7,028.10 USD - $8,548.10 USD
$7,028.10 USD - $8,548.10 USD
$7,028.10 USD
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$1,998.00 USD - $2,198.00 USD
$1,998.00 USD
$1,898.10 USD - $2,088.10 USD
$1,898.10 USD - $2,088.10 USD
$1,898.10 USD

William Optics Fluorostar 91

91mm Aperture Apochromatic Triplet FPL-53 Glass Focal Length: 540mm Focal Ratio: f/5.9 Strehl Ratio: > 0.95 3.3" Dual-Speed Rack & Pinion F...

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$1,998.00 USD - $2,198.00 USD
$1,998.00 USD
$1,898.10 USD - $2,088.10 USD
$1,898.10 USD - $2,088.10 USD
$1,898.10 USD
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$1,098.00 USD
$1,098.00 USD - $1,098.00 USD
$1,098.00 USD
$1,043.10 USD
$1,043.10 USD - $1,043.10 USD
$1,043.10 USD

William Optics Gran Turismo 71 APO Triplet

71mm Triplet Apochromatic Lens 419mm Focal Length (f/5.9) 44mm Image Circle 3-Element Objective with FPL-53 Glass 2.5" Rack & Pinion Focuser O...

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$1,098.00 USD
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$1,098.00 USD
$1,043.10 USD
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$2,198.00 USD
$2,198.00 USD - $2,198.00 USD
$2,198.00 USD
$2,088.10 USD
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$2,088.10 USD

William Optics Gran Turismo WIFD 81

81mm Aperture Apochromatic Triplet Refractor FPL-53 Glass from Ohara, Japan 478mm Focal Length (f/5.9) >Full Frame (45mm) Image Circle William ...

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$2,198.00 USD
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$2,198.00 USD
$2,088.10 USD
$2,088.10 USD - $2,088.10 USD
$2,088.10 USD
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$398.00 USD - $438.00 USD
$398.00 USD
$378.10 USD - $416.10 USD
$378.10 USD - $416.10 USD
$378.10 USD

William Optics GuideStar 61

FPL53 ED Air-Spaced Doublet Lens Dual-Purpose Guide Scope and Imaging Telescope Draw-Tube (Push-Pull) Focuser Rotating Lens Assembly for Fine Focu...

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$398.00 USD - $438.00 USD
$398.00 USD
$378.10 USD - $416.10 USD
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$378.10 USD
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$276.00 USD - $288.00 USD
$276.00 USD
$262.20 USD - $273.60 USD
$262.20 USD - $273.60 USD
$262.20 USD

William Optics High Latitude WO Vixen Style Base Mount

Designed for the iOptron SkyGuider Pro and Sky-Watcher Star Adventurer Enables stable, precise polar alignment at high latitudes CNC-machined Vixe...

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$276.00 USD - $288.00 USD
$276.00 USD
$262.20 USD - $273.60 USD
$262.20 USD - $273.60 USD
$262.20 USD
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$60.00 USD
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$60.00 USD
$57.00 USD
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$57.00 USD

William Optics Image Plane Tilt Adjuster

Designed for the first-generation William Optics RedCat 51 (V1) astrograph Corrects image plane tilt for perfectly round stars across the frame Ad...

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$60.00 USD
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$60.00 USD
$57.00 USD
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$39.00 USD
$39.00 USD - $39.00 USD
$39.00 USD
$37.05 USD
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$37.05 USD

William Optics iOptron Skyguider Pro Dec Adapter

Mounts a Vixen-Style Saddle on the iOptron SkyGuider Pro Doubles as a Riser Block Optimized for Wide-Field Astrophotography Setups Lightweight, A...

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$39.00 USD
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$39.00 USD
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$91.00 USD
$91.00 USD - $91.00 USD
$91.00 USD
$86.45 USD
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$86.45 USD

William Optics Long Version Vixen-Style Dovetail Plate

290 mm Extended Length for Balancing Standard Vixen-Style Dovetail Profile Weighs 0.64 kg (1.42 lbs) 90 mm Wide Platform for Stability Descript...

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$91.00 USD
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$91.00 USD
$86.45 USD
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$86.45 USD
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$58.00 USD
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$58.00 USD
$55.10 USD
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William Optics Longer adjusting adapter for FLAT68III, FLAT7A

Connects FLAT68III & FLAT7A Flatteners to M48 Imaging Trains Provides a Fixed 45mm Optical Length Input Thread: M80 x 0.75 Output Thread: M48 ...

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$58.00 USD
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$116.00 USD - $139.00 USD
$116.00 USD
$110.20 USD - $132.05 USD
$110.20 USD - $132.05 USD
$110.20 USD

William Optics Losmandy Style Type D

Length: 400 mm Weight: 1.44 kg / 3.17 lbs Width: 105 mm Dovetail Type: Losmandy D-Style Description FAQ Specifications In the Box Warranty ...

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$116.00 USD - $139.00 USD
$116.00 USD
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$110.20 USD
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What Goes on Sale and Why

Understanding why an item is discounted helps you judge whether it is the right purchase, so we are explicit about the reason wherever we can be.

  • Open-box and display units: Returned or demonstrated equipment that has been inspected and tested here, typically indistinguishable from new in use.
  • Superseded models: Products replaced by a newer revision, often with only minor changes and full parts and warranty support remaining.
  • Overstock: Items we hold more of than current demand justifies, discounted while the stock lasts.
  • Seasonal accessories: Dew control, cases and cold-weather items that move seasonally and are reduced outside their peak.
  • End-of-line accessories: Adapters, rings and small parts from lines being retired, which remain perfectly serviceable.
  • Used equipment: Our separate collection of tested second-hand gear, for buyers comfortable with pre-owned optics and mounts.

Why Choose David Astro for Discounted Astronomy Gear

A discount is only a good deal if the item is right for your setup and stays supported afterwards.

  • Compatibility checked before you commit: We will confirm a sale item actually fits your telescope or mount, because a bargain adapter that does not fit is not a bargain.
  • Condition stated honestly: Open-box and display items are described as what they are, with any cosmetic marks noted.
  • Full warranty on new items: Discounted new stock carries the same manufacturer warranty as anything else we sell, handled domestically.
  • Canadian stock: Sale items ship from Canada without duties or brokerage fees for Canadian buyers.
  • Same support after the sale: Setup help, spacing calculations and in-house diagnostics apply to discounted purchases too.

Astronomy Sales in Canada — Frequently Asked Questions

Do sale items carry a warranty?
New discounted items carry the full manufacturer warranty. Open-box items are covered as stated on the listing, and we handle any claim domestically rather than routing it internationally.
Is an open-box item risky?
Not in our experience. Everything is inspected and functionally tested here before it is relisted, and anything with a cosmetic mark is described. Optics are checked for coating condition and collimation.
Can I still get support on a discontinued model?
Generally yes. We stock spare parts and adapters for many superseded models, and we say on the listing where parts availability is limited.
How long do sale prices last?
Until the stock is gone. These are finite quantities rather than a recurring promotion, so an item that disappears from this collection has usually sold rather than returned to full price.

Found something here?

Ask us before you order and we will confirm it fits your setup. Canadian stock, full support.