Ultra-Cat 76 Anniversary Edition: William Optics announces a Commemorative Telescope

William Optics is marking its 30th year with a special release. The Ultra-Cat 76 Anniversary Edition celebrates the company’s long-running “Cat” astrographs. The Cat family began its modern rise with the introduction of the RedCat 51 in 2019. That small refractor became a favorite starter scope for imagers worldwide. In 2024, William Optics introduced its WIFD internal focuser. In 2025, it launched the Ultra-Cat series with a new five-element Petzval design. The company reports that the 91 mm and 108 mm models sold strongly and set a high standard for wide-field work. The 76 mm enters as the commemorative model for the anniversary year.

This Anniversary Edition is a true limited run. William Optics will build only 100 units, each with an individual number. Every tube carries a laser-engraved emblem of a cat wrapped around “30.” A printed 30th-anniversary certificate ships with each scope. These touches aim to make the 76 a collectible as well as a working instrument.

The Ultra-Cat 76 telescope

At its core, the Ultra-Cat 76 is a fast, flat-field astrograph. The objective is 76 mm in diameter with a focal length of 365 mm. That yields a bright f/4.8 system. The optical layout is a five-element advanced Petzval. William Optics lists two Super ED elements, one ED element, one lanthanum element, and one “X-Element.” The field is designed to be flat out of the box. No external flattener is required.

The image circle is 50 mm. That covers full-frame sensors and gives headroom for careful framing. William Optics presents the 76 as “full-frame recommended,” with compatibility extending to some medium-format cameras. The company emphasizes the scope’s modern sensor readiness across formats.

Focusing help is built into the front cap. The retractable dew shield houses a patented Bahtinov mask. It is made from optical-grade PMMA and is designed to give quick, repeatable focus.

WIFD focusing and STX tilt control

The telescope ships with the WIFD rack-and-pinion focuser. WIFD moves the focusing mechanism to the center of the tube. The design aims to remove tube tilt from heavy cameras and filter wheels. The optics slide on an internal rail, and the mass stays balanced around the tube. William Optics also stresses that WIFD’s internal layout keeps the mechanism dust-free and easy to maintain. The focuser is compatible with popular electronic focus motors, and it does not need a separate bracket.

Back-focus tuning often ends with a separate tilt plate. William Optics integrates its new Sensor Tilt Xterminator, or STX, with the Ultra-Cat line. STX gives side access to four adjustment screws. The mechanism works like a see-saw and shortens the time needed to level the sensor. You can tweak the tilt without removing the camera. The STX replaces a layer of threaded filters with a rigid plate to reduce flex.

Pricing, availability, and what’s special

William Optics Ultra-Cat 76 Anniversary Edition is limited to 100 units. Each tube is numbered and ships with the special engraving and certificate. The company positions the 76 as the most approachable Ultra-Cat, echoing how the RedCat 51 became a gateway scope.

The anniversary edition telescope will be available to order from the official website beginning in October 2025. We do not have a word on the exact date and price. For context, the regular Ultra-Cat 76 is available for $1,888.

Clear skies!

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