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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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CA$109.00
CA$109.00 - CA$109.00
CA$109.00
CA$104.00
CA$104.00 - CA$104.00
CA$104.00

William Optics Saddle Plate for Vixen-Style Dovetail Plate - 90mm

WO-M-SP90RC-RD
1 in stock

Length: 90 mm Dovetail Type: Vixen-Style Weight: 230 g (0.51 lbs) Full-Length, Non-Marring Clamp Signature William Optics Red Anodized Finish D...

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CA$109.00
CA$109.00 - CA$109.00
CA$109.00
CA$104.00
CA$104.00 - CA$104.00
CA$104.00
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CA$62.00
CA$62.00 - CA$62.00
CA$62.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00

William Optics SCT Connection for WO Diagonals - Gold

WO-D-SCT-TA

Connects a 2" SCT Thread to a William Optics 2" Diagonal Adds 13.8 mm of Optical Length Female Thread: M50.8 Male Thread: M48 Signature William Op...

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CA$62.00
CA$62.00 - CA$62.00
CA$62.00
CA$59.00
CA$59.00 - CA$59.00
CA$59.00
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CA$105.00
CA$105.00 - CA$105.00
CA$105.00
CA$100.00
CA$100.00 - CA$100.00
CA$100.00

William Optics Slide-Base 50mm Guiding Rings

WO-M-GR50SL
1 in stock

Securely holds 50mm-class guidescopes and finders with tubes from 33 to 58 mm Slide-base design allows for fore-and-aft adjustment for precise bal...

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CA$105.00
CA$105.00 - CA$105.00
CA$105.00
CA$100.00
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CA$100.00
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CA$92.00
CA$92.00 - CA$92.00
CA$92.00
CA$87.00
CA$87.00 - CA$87.00
CA$87.00

William Optics Slide-Base 50mm Guiding Rings - No Adjustments Screws

WO-M-GR50IISL

Seamlessly integrate with your existing astrophotography gear. Ensures stable attachment of your telescope to your mount. Description In th...

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CA$92.00
CA$92.00 - CA$92.00
CA$92.00
CA$87.00
CA$87.00 - CA$87.00
CA$87.00
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CA$189.00
CA$189.00 - CA$189.00
CA$189.00
CA$180.00
CA$180.00 - CA$180.00
CA$180.00

William Optics Slide-Base UniGuide 32mm Scope

Options available
7 variants in stock

32mm Doublet Objective Lens Fast f/3.75 Focal Ratio 120mm Focal Length Integrated Vixen/Synta-Style Slide-Base Ultra-Lightweight at 0.23 kg (0.51 ...

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CA$189.00
CA$189.00 - CA$189.00
CA$189.00
CA$180.00
CA$180.00 - CA$180.00
CA$180.00
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CA$275.00
CA$275.00 - CA$275.00
CA$275.00
CA$261.00
CA$261.00 - CA$261.00
CA$261.00

William Optics Slide-Base UniGuide 50mm Scope

Options available
7 variants in stock

50mm Aperture Doublet Lens 200mm Focal Length (f/4.0) Integrated 1.25" RotoLock Adapter Slide-Base for William Optics Handles Total Weight: 0.5 kg...

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CA$275.00
CA$275.00 - CA$275.00
CA$275.00
CA$261.00
CA$261.00 - CA$261.00
CA$261.00
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CA$156.00
CA$156.00 - CA$156.00
CA$156.00
CA$148.00
CA$148.00 - CA$148.00
CA$148.00

William Optics SPL 55° 12.5mm Eyepiece - 1.25"

WO-E-SPL12.5

1.25-inch eyepiece with 55° apparent field of view 12.5mm focal length for medium-high magnification viewing Description The W...

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CA$156.00
CA$156.00 - CA$156.00
CA$156.00
CA$148.00
CA$148.00 - CA$148.00
CA$148.00
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CA$660.00
CA$660.00 - CA$660.00
CA$660.00
CA$627.00
CA$627.00 - CA$627.00
CA$627.00

William Optics STC Astro Duo-Narrowband Filter

WO-YF-STC-ADN

Dual-Bandpass for H-Alpha and Oxygen-III Suppresses Urban Light Pollution Ion Beam-Assisted Deposition (IBAD) Coatings High Durability and Easy-to...

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CA$660.00
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CA$660.00
CA$627.00
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CA$627.00
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CA$328.00
CA$328.00 - CA$328.00
CA$328.00
CA$312.00
CA$312.00 - CA$312.00
CA$312.00

William Optics STC Ultra Layer Astro Multispectra Filter - 48mm

WO-YF-STC-M48

48mm (M48) Filter Size Multi-Bandpass Light Pollution Suppression Passes H-α, H-β, and OIII Emission Lines Schott B270 Optical Glass Substrate STC...

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CA$328.00
CA$328.00 - CA$328.00
CA$328.00
CA$312.00
CA$312.00 - CA$312.00
CA$312.00
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CA$190.00
CA$190.00 - CA$190.00
CA$190.00
CA$181.00
CA$181.00 - CA$181.00
CA$181.00

William Optics STL Adapter for FLT Flattener

WO-P-STL

Connects SBIG STL-11000 Series CCD Cameras Attaches to P-FLAT68 Field Flatteners via M80 Female Thread Provides a Precise 69 mm Optical Path Lengt...

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CA$190.00
CA$190.00 - CA$190.00
CA$190.00
CA$181.00
CA$181.00 - CA$181.00
CA$181.00
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CA$149.00
CA$149.00 - CA$149.00
CA$149.00
CA$142.00
CA$142.00 - CA$142.00
CA$142.00

William Optics Super High Precision COPPER T-Mount for Canon EOS Full Frame

WO-YE-TR-BR48-C
1 in stock

Solid Copper Construction for Maximum Rigidity M48 (2") Female Thread for Wide-Field Correctors Connects to Canon EOS Camera Bodies Precise 10.6 m...

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CA$149.00
CA$149.00 - CA$149.00
CA$149.00
CA$142.00
CA$142.00 - CA$142.00
CA$142.00
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CA$149.00
CA$149.00 - CA$149.00
CA$149.00
CA$142.00
CA$142.00 - CA$142.00
CA$142.00

William Optics Super High Precision COPPER T-Mount for Nikon Full Frame

WO-YE-TR-BR48-N

Solid Copper Construction for Maximum Rigidity M48 x 0.75 Female Thread for Wide-Field Correctors Designed for Nikon F-Mount Full-Frame Cameras Pr...

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CA$149.00
CA$149.00 - CA$149.00
CA$149.00
CA$142.00
CA$142.00 - CA$142.00
CA$142.00
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CA$215.00
CA$215.00 - CA$215.00
CA$215.00
CA$204.00
CA$204.00 - CA$204.00
CA$204.00

William Optics SWAN 72° 40mm Eyepiece - 2"

WO-E-SWA40
4 in stock

40mm Focal Length 72° Apparent Field of View 2" Diameter Barrel 28mm Long Eye Relief Parfocal Design Description FAQ Specifications In the Box ...

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CA$215.00
CA$215.00 - CA$215.00
CA$215.00
CA$204.00
CA$204.00 - CA$204.00
CA$204.00
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William Optics Ultra Flat 132 (0.79x Reducer)
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CA$1,474.00
CA$1,474.00 - CA$1,474.00
CA$1,474.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00

William Optics Ultra Flat 132 (0.79x Reducer)

WO-P-FLAT-132

Reduces focal ratio by a factor of 0.79x Provides a flat field for Full Frame, APS-C, and M4/3 sensors 3-element, 3-group optical design Connects ...

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CA$1,474.00
CA$1,474.00 - CA$1,474.00
CA$1,474.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00
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William Optics Ultra Flat 156 (0.79x Reducer)
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CA$1,474.00
CA$1,474.00 - CA$1,474.00
CA$1,474.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00

William Optics Ultra Flat 156 (0.79x Reducer)

WO-P-FLAT-156

Reduces focal ratio by a factor of 0.79x Designed for Medium Format, Full Frame, and APS-C sensors 3-element, 3-group optical design 75.5mm optica...

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CA$1,474.00
CA$1,474.00 - CA$1,474.00
CA$1,474.00
CA$1,400.00
CA$1,400.00 - CA$1,400.00
CA$1,400.00
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William Optics Ultra-Cat 131 f/4.9 Petzval Astrograph
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CA$7,449.00
CA$7,449.00 - CA$7,449.00
CA$7,449.00
CA$7,077.00
CA$7,077.00 - CA$7,077.00
CA$7,077.00

William Optics Ultra-Cat 131 f/4.9 Petzval Astrograph

WO-T-C-131BR

131mm Aperture 648mm Focal Length (f/4.9) 5-Element Advanced Petzval Optical Design 60mm Flat-Field Image Circle Patented WIFD Internal Focuser 13...

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CA$7,449.00
CA$7,449.00 - CA$7,449.00
CA$7,449.00
CA$7,077.00
CA$7,077.00 - CA$7,077.00
CA$7,077.00
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CA$5,517.00
CA$5,517.00 - CA$5,517.00
CA$5,517.00
CA$5,076.00
CA$5,076.00 - CA$5,076.00
CA$5,076.00

William Optics UltraCat 108 f/4.8 WIFD

WO-T-C-108BR
1 in stock

108mm Aperture, 5-Element Advanced Petzval Optical Design Fast f/4.8 Focal Ratio with 518mm Focal Length Massive 60mm Flat-Field Image Circle Pate...

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CA$5,517.00
CA$5,517.00 - CA$5,517.00
CA$5,517.00
CA$5,076.00
CA$5,076.00 - CA$5,076.00
CA$5,076.00
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CA$1,929.00
CA$1,929.00 - CA$1,929.00
CA$1,929.00
CA$1,397.00
CA$1,397.00 - CA$1,397.00
CA$1,397.00

William Optics UltraCat 56 f/4.8 WIFD

WO-T-C-56BR
6 in stock

56mm Aperture, 269mm Focal Length (f/4.8) 5-Element Advanced Petzval Optical Design 50mm Image Circle for Full-Frame & Larger Sensors William ...

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CA$1,929.00
CA$1,929.00 - CA$1,929.00
CA$1,929.00
CA$1,397.00
CA$1,397.00 - CA$1,397.00
CA$1,397.00
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William Optics UltraCat 56 with Elite Drawer OAG Kit
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CA$2,472.00
CA$2,472.00 - CA$2,472.00
CA$2,472.00
CA$1,674.00
CA$1,674.00 - CA$1,674.00
CA$1,674.00

William Optics UltraCat 56 f/4.8 WIFD with Elite Drawer OAG Kit

WO-T-C-56BR-OAG

UltraCat 56 f/4.8 WIFD Astrograph + Elite Drawer OAG Kit 56mm Aperture, 269mm Focal Length (f/4.8) 5-Element Petzval Design, 50mm Image Circle, No...

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CA$2,472.00
CA$2,472.00 - CA$2,472.00
CA$2,472.00
CA$1,674.00
CA$1,674.00 - CA$1,674.00
CA$1,674.00
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CA$3,033.00
CA$3,033.00 - CA$3,033.00
CA$3,033.00
CA$2,790.00
CA$2,790.00 - CA$2,790.00
CA$2,790.00

William Optics UltraCat 76 f/4.8 WIFD

WO-T-C-76BR
2 in stock

76 mm Aperture, 365 mm Focal Length (f/4.8) 5-Element Advanced Petzval Optical Design 50 mm Corrected Image Circle William Optics Internal Focusin...

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CA$3,033.00
CA$3,033.00 - CA$3,033.00
CA$3,033.00
CA$2,790.00
CA$2,790.00 - CA$2,790.00
CA$2,790.00
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CA$105.00
CA$105.00 - CA$105.00
CA$105.00
CA$100.00
CA$100.00 - CA$100.00
CA$100.00

William Optics Vixen Style Finder Mounting Bracket

WO-M-FB50-B
1 in stock

Vixen-Style Dovetail Base Secure Mounting for Finderscopes and Guide Scopes Durable Metal Construction Fits William Optics Scopes with Standard R&...

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CA$105.00
CA$105.00 - CA$105.00
CA$105.00
CA$100.00
CA$100.00 - CA$100.00
CA$100.00
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CA$115.00
CA$115.00 - CA$115.00
CA$115.00
CA$109.00
CA$109.00 - CA$109.00
CA$109.00

William Optics Vixen Style Finder Mounting Bracket for RedCat - Black Base

WO-M-FB50-RC-BB

Seamlessly integrate with your existing astrophotography gear. Ensures stable attachment of your telescope to your mount. Description In th...

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CA$115.00
CA$115.00 - CA$115.00
CA$115.00
CA$109.00
CA$109.00 - CA$109.00
CA$109.00
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CA$32.00
CA$32.00 - CA$32.00
CA$32.00
CA$30.00
CA$30.00 - CA$30.00
CA$30.00

William Optics Vixen Style Mounting Base

WO-BAFM-ST001II
3 in stock

Compact 38 mm x 42 mm Mounting Base Standard Mini-Vixen Dovetail Profile Ultra-Lightweight at Just 45 g (0.10 lbs) Provides a Secure Attachment Po...

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CA$32.00
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CA$32.00
CA$30.00
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CA$30.00
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CA$56.00
CA$56.00 - CA$56.00
CA$56.00
CA$53.00
CA$53.00 - CA$53.00
CA$53.00

William Optics Vixen-Style 8" Dovetail Plate - Black

WO-M-PVB

Designed to fit Vixen-style dovetail mounts Ensures durability and a lightweight design. Description The William Optics Vixen-...

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CA$56.00
CA$56.00 - CA$56.00
CA$56.00
CA$53.00
CA$53.00 - CA$53.00
CA$53.00
Sold out

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.