Ultra-Cat 76 · 30th Anniversary Limited Edition
The Ultra-Cat 76 · 30th Anniversary Edition is a commemorative refractor celebrating three decades of William Optics craftsmanship and innovation. Built upon the acclaimed five-element advanced Petzval optical design, this limited edition of 100 units worldwide combines uncompromising astrophotography performance with a symbolic anniversary finish.
Featuring a unique laser-engraved emblem of a cat embracing “30” ,personally hand-signed by founder William Yang on the lens cover, and accompanied by a 30th Anniversary Certificate, the Ultra-Cat 76 is not only a professional imaging instrument but also a collector’s piece that honors the Cat series legacy.
Key Features:
Advanced 5-Element Petzval Optics
Eliminates field curvature, ensuring sharp, edge-to-edge stars without additional flatteners.
50mm Large Image Circle
Fully supports Full Frame cameras, APS-C and M4/3 sensors for optimal performance. Compatible with Medium Format.
Fast f/4.8 Optics
Superior light-gathering capability, enabling deep-sky imaging with shorter exposure times.
WIFD (William’s Internal Focuser Design)
Patented internal rack-and-pinion focuser ensures stable and precise focusing.
No vignetting or balance issues — ideal for astrophotography.
Compatible with EAF (Electronic Automatic Focuser) for precision focus control.
Sensor Tilt Xterminator (STX) & Rotator
Integrated tilt adjuster eliminates sensor misalignment, ensuring uniform image sharpness.
No Flattener Required
The optical design naturally corrects field curvature, simplifying setup.
Anti-Shrink Lens Cell Technology
Reduces thermal expansion effects, maintaining perfect optical alignment in any climate.
Patented Bahtinov Mask for Focusing
Built-in focusing aid ensures pinpoint star sharpness with ease.
Premium Build & Ergonomic Design
Lightweight yet robust (4.31 kg / 9.5 lbs) construction with a sleek anodized finish.
Patented handle bar design for enhanced portability and ease of use.
Versatile Camera Compatibility
Supports Canon EF, RF, Nikon F,Z, Sony E, Pentax K, MFT, and FUJI X mounts.
Anniversary Special
UniGuide 32mm f/3.75
Enhance your astrophotography setup with the William Optics UniGuide 32mm f/3.75, a compact and versatile guide scope designed for precision and ease of use. This lightweight guide scope weighs only 240g and features a high-quality, fully multi-coated 32mm objective lens, ensuring bright, clear guiding stars.
The UniGuide 32mm offers a fast f/3.75 focal ratio and a 120mm focal length, ideal for accurately tracking celestial objects. It comes equipped with a slide-base Vixen/Synta-style rail for easy attachment directly to compatible William Optics telescopes, streamlining your setup and eliminating the need for conventional guidescope rings.
This guide scope is compatible with a variety of guide cameras, including popular models like the ZWO ASI120 Mini and Starlight Xpress Lodestars, thanks to its 1.25" adaptor and M42 thread. Available in four stylish colors—red, gold, space grey, and blue—the UniGuide 32mm not only performs superbly but also adds a touch of elegance to your astronomical equipment.
Whether you are a novice astrophotographer or a seasoned veteran, the William Optics UniGuide 32mm guide scope is an excellent addition to your astronomical toolkit, helping you achieve perfect tracking for flawless long-exposure images.
- Lens Type
- 5-Element Advanced Petzval
- Lens Elements
- Super ED Glass x2 ED Glass x1 Lanthanum Glass x1 X-Element x1
- Focal Length
- 365 公釐
- Diameter
- 76 公釐
- Focal Ratio
- f/4.8
- Image circle
- 50 公釐
- Focuser
- WIFD R&P Focuser Compatible with EAF
- Focus travel
- 0-20 mm (Ruler to 21mm)
- Adapter Included
- Sensor Tilt Xterminator Rotator M54, M48 Camera Adapters
- Optional Flattener
- No Flattener Required
- T-Mount Support
- Canon EF, RF Nikon F, Z Sony E Pentax K MFT (M4/3) FUJI X
- Camera Format
- Medium Format (Compatible) Full Frame (Recommended) APS-C M4/3
- Dovetail Type
- Vixen ↔︎ Arca-Swiss
- Tube Length
- 363 公釐 - 415 公釐
- OTA Weight
- 3.81 公斤 / 8.4 lbs
- Total Weight
- 4.98 公斤 / 10.98 lbs
選擇選項
What's in the box
Main Tube
Bahtinov Cap
M48, M54 adapter with wrench
Dual-side Plate
Mounting Ring Handle bar
Riser Blocks
Soft Carry Case
Allen Key Set
Three Decades of Vision, Inspiring Generations to Come.
Celebrating 30 years of William Optics craftsmanship, the Ultra-Cat 76 brings the acclaimed five-element Petzval design into a commemorative edition. Compact yet powerful, it delivers premium optical performance with a special anniversary finish, engraved emblem, and serialized marking—a telescope that honors the past and inspires the future.
Limited 100 Units
Individually numbered to underscore its exclusivity as a commemorative edition.
Symbolic Laser Engraving
A unique design of a cat embracing the number “30,” honoring the legacy of the Cat series.
Founder’s Signature
Personally hand-signed by William Yang on the lens cover, every telescope is a unique collector’s piece.
Commemorative Certificate
Accompanied by an official 30th Anniversary certificate to mark its special place in William Optics history.
Advanced Petzval
Researched and developed by WO, the innovative 5-element Petzval design redefines telescope optics. This advanced system achieves a flawless spot diagram across a medium-format image circle.
Extra-low Dispersion (ED) glasses
Contains 2 Super ED, 1 ED glasses and lanthanum lenses with advanced fully multi-coated, delivering sharp, vibrant images with true-to-life colors, significantly reducing chromatic aberration.
Needs NO Flattener
The Petzval design inherently flattens the field, eliminating the need for an external field flattener.
Never easier to capture deep sky objects
comprehensive configuration
Precision Imaging Adjustment
Sensor Tilt Xterminator (STX)
The built-in STX allows quick side-access tilt adjustments without removing the camera.
Learn More
Camera Angle Rotator
Correct any angular discrepancies, and get the perfect angle on your images.
Compatible with Electronic Motorized Devices
Hassle Free Installation
( No Mounting Bracket Kit required )
Leading the market
Wo patented design
The Ultra-Cat 76 · 30th Anniversary Limited Edition holds three unique patents, ensuring easy and perfect focusing along with precise coaxial image quality, preventing draw tube tilt issues caused by optical misalignment.
:
Internal Focuser
The WIFD focusing Design relocates the focuser to the center of the telescope, addresses the issue of tube tilt caused by the weight of accessories and cameras.
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Integrated Bahtinov mask
Laser engraved on high-definition and stable optical PMMA. Enhances astrophotography experience with quick and accurate adjustments.
CAT Handle Bar
Crafts for enhanced portability and versatility.
Mounting Ring
Designed for seamless functionality without compromising on stability. Engineered with wide surface contacts, this innovative ring ensures a secure fit while enabling fast, easy detachment.
