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William Optics

William Optics

William Optics has built its reputation on small apochromatic astrographs that are genuinely portable, mechanically well finished and easy to bring to focus — the RedCat and Zenithstar families in particular have become default recommendations for imagers who want wide fields without a heavy mount. David Astro stocks William Optics products in Canada, shipping from Canadian inventory.

We image with these telescopes here, and can tell you where the fixed back-focus of the Petzval designs simplifies your life and where a longer focal length model would serve your targets better.

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William Optics Image Plane Tilt Adjuster

WO-M-FD-RC51

Designed exclusively for the William Optics RedCat 51 astrograph Corrects image plane tilt for perfectly round stars across the frame Adds only 12...

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$60.00 - $60.00
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William Optics 2x Barlow Nosepiece for Binoviewer

WO-E-BINO-B2
6 in stock

Provides 2x magnification Enables binoviewers to reach focus in most telescopes Standard 1.25" nosepiece format Threads directly onto the binoview...

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$59.00 - $59.00
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William Optics 75mm -110mm Bahtinov Focusing Mask

WO-BM-DS-GR45

Fits Telescope Dew Shields from 75mm to 110mm Creates Sharp Diffraction Spikes for Precise Focusing Ideal for Small Apochromatic Refractors and As...

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$59.00 - $59.00
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William Optics 30mm Flattener Adapter
$58.00 - $58.00
$58.00
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$58.00

William Optics 30mm Flattener Adapter

WO-AD-M80TOM54

30mm Optical Length Connects M80 x 0.75 to M54 x 0.75 Threads For William Optics Flat68III & Flat7A Flatteners Description FAQ Specificatio...

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$58.00 - $58.00
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William Optics Longer adjusting adapter for FLAT68III, FLAT7A

WO-AD-M80-45-M48

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

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William Optics 2"-1.25" RotoLock Visual Back Adapter

Options available

Converts 2" focusers to a 1.25" holder Innovative RotoLock self-centering mechanism Dual input: 2" push-in barrel and female M48 threads Adds 38 m...

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$58.00 - $58.00
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$55.00 - $55.00
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William Optics 48mm T-Mount for Fuji FX - Black

WO-TM-FJ-X-M48
1 in stock

Connects M48-threaded correctors to Fujifilm X-mount (Fuji FX) mirrorless cameras Wide 48mm aperture minimizes vignetting on APS-C sensors Precise...

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William Optics 48mm T-Mount for Sony E - Black

WO-TM-SN-E-M48
3 in stock

Connects Sony E-mount cameras to M48 accessories Provides a precise 36.7 mm optical length M48 (female) threads reduce vignetting on large sensors...

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$51.76 - $58.00
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$51.76

William Optics DSD 245 Plate

Options available
2 variants in stock

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 - $58.00
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William Optics Cat Mounting Ring

WO-M-MR50RC-BL

50mm Inner Diameter Solid Aluminum Construction Anodized Blue Finish 1/4"-20 Threaded Mounting Holes Weight: 4.9 oz (140 g) Description FAQ Spe...

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William Optics 120mm Saddle Handle Bar

WO-M-HC120BL
1 in stock

120 mm Length 44 mm Width Integrated Mini-Vixen Style Saddle Patented Handlebar Design Lightweight and Durable Construction Description FAQ Spe...

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$48.00 - $48.00
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William Optics M63 Female to 2" Push-in Adapter for P-FLAT6AIII

WO-YE-M63F-2IN-PI
1 in stock

Connects P-FLAT6AIII Flattener to 2" Focuser Female M63 Threads for Flattener Connection Male 2" Push-in Barrel for Focuser Internal M48 Female Th...

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$48.00 - $48.00
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William Optics DSD 210 Plate

Options available
3 variants in stock

210 mm total length for balancing flexibility Dual-profile fits both Vixen-style and Arca-Swiss clamps 41.5 mm width provides a stable mounting su...

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$45.00 - $48.00
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William Optics Micro 4/3 48mm T-Mount for Olympus - Black

WO-TM-MFT-M48
3 in stock

Connects M48 Correctors to Olympus Micro 4/3 Cameras Fixed 35.6 mm Optical Length for Precise Back Focus Light-In Connection: M48 (Female) Thread ...

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William Optics SCT Connection for WO Diagonals - Gold

WO-D-SCT-TA

Connects M50.8 Male to M48 Female Threads Adds 13.8 mm of Optical Length Female Thread: M50.8 Male Thread: M48 Signature William Optics Gold Anodi...

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William Optics Vixen-Style 8" Dovetail Plate - Red

WO-M-PVR

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

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$39.00 - $39.00
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Sold out
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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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$39.00 - $39.00
$39.00
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Sold out
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William Optics 48mm T-Mount for Pentax K - Black

WO-TM-PT-K-M48
1 in stock

Connects Pentax K-Mount Cameras to M48 Accessories Precisely machined 9.3 mm optical length achieves exact 55mm back focus when combined with came...

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William Optics 48mm T-Mount for Canon

WO-TM-CN-EOS-M48
4 in stock

Connects M48 (2-inch) Threaded Correctors to Canon EOS Cameras Wide M48 Aperture Eliminates Vignetting on Full-Frame Sensors Adds a Precise 10.6 m...

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William Optics iOptron Skyguider Pro Dec Adapter

WO-M-IOPSG-SPM

Directly Mounts William Optics Scopes to iOptron Skyguider Pro Replaces the Standard Declination (DEC) Bracket Low-Profile Design for Enhanced Sta...

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William Optics M48 Push-in Nosepiece for WO 2" Diagonals & UniGuide Scope

WO-WD-DIG2A
1 in stock

Connects M48 Threaded Accessories to 2" Push-in Focusers Female M48 Threads for 2" Filter Attachment Adds a Fixed 36 mm of Optical Length Male M48...

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$39.00 - $39.00
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$39.00

William Optics 48mm T-Mount for Nikon F

WO-TM-NK-F-M48
2 in stock

Connects M48 Accessories to Nikon F-Mount Cameras Precisely machined 8.2 mm optical length achieves exact 55mm back focus when combined with camer...

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$39.00 - $39.00
$39.00
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$36.00 - $38.00
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$36.00

William Optics DSD 110 Plate

Options available
5 variants in stock

Dual Saddle Plate Design Accepts Vixen-Style Dovetails Accepts Losmandy D-Style Dovetails Precision CNC-Machined Construction Durable Anodized Fin...

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$36.00 - $38.00
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$36.00
$34.00 - $34.00
$34.00
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$34.00

William Optics Extension Bar for iOptron Skyguider Pro

WO-M-IO-EB20RD
2 in stock

Adds a declination axis to the iOptron SkyGuider Pro Specifically designed to fit the iOptron SkyGuider Pro Description The Wi...

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$34.00 - $34.00
$34.00
$34.00 - $34.00
$34.00

The William Optics Range

The line divides fairly cleanly between Petzval astrographs with built-in field correction and traditional doublets and triplets that use a separate flattener.

  • RedCat and Petzval astrographs: Four-element designs with the flattener integrated, giving a flat field at a fixed back-focus with no spacing calculation required — the simplest imaging optics to set up correctly.
  • Zenithstar apochromatic refractors: Compact FPL-53 doublets from 61 mm upward, popular as first imaging telescopes and as guide or companion scopes on larger rigs.
  • GT and FLT triplet refractors: Larger apochromatic triplets for imagers who want more aperture and focal length while keeping a refractor's convenience.
  • UniGuide guide scopes: Rigid guide scopes with integrated mounting that avoids the flexure common to ring-and-bracket guide setups.
  • RotoLock and mechanical accessories: Rotating locking collars, dovetails, tube rings and Bahtinov masks designed to fit the tubes precisely.
  • Diagonals and eyepieces: Dielectric diagonals and eyepiece lines matched to the refractors for visual use.

Why Choose David Astro for William Optics

These telescopes are straightforward to use and easy to buy in the wrong focal length. That is where the advice matters.

  • Focal length matched to targets: We calculate the field of view your sensor will get on each model, so you can see whether your target actually fits before ordering.
  • Petzval back-focus supplied: The integrated designs have a fixed spacing requirement, and we provide the exact adapter list for your camera and filter setup.
  • Authorized dealer: Full manufacturer warranty with verified authenticity, handled domestically in Canada.
  • Canadian stock: Ships from Canada with no duties or brokerage fees for Canadian orders.
  • Support after first light: Help diagnosing tilt, spacing and star shape once the telescope is on the sky.

William Optics in Canada — Frequently Asked Questions

Do RedCat telescopes need a flattener?
No. The Petzval design includes field correction, so you only need to hit the specified back-focus to the camera sensor. That is one of the main reasons they are recommended to first-time imagers.
Which focal length should I choose?
It depends on your target size and sensor. Around 250 mm suits large nebulae and the Andromeda galaxy; 400 to 600 mm frames most emission nebulae well; beyond that you are into small galaxies and planetary nebulae, which also demands better guiding.
Can these work as guide scopes?
The smaller Zenithstars and the UniGuide range are commonly used this way. The key advantage of a purpose-built guide scope is rigidity — a flexing guide scope produces errors that guiding cannot correct.
Is warranty handled in Canada?
Yes. As an authorized dealer we process warranty and service claims here, without international shipping or customs paperwork.

Choosing a focal length?

Send us your camera and your target list and we will show you the framing. Canadian stock, full warranty.