William Optics

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.