William Optics UltraCat 56 f/4.8 WIFD Petzval APO Refractor - T-C-56BR

The William Optics UltraCat 56 is a cutting-edge 56mm f/4.8 apochromatic refractor designed for astrophotographers who demand top-tier performance. Featuring a 5-element advanced Petzval optical design and a fast f/4.8 focal ratio, the UltraCat 56 delivers breathtaking edge-to-edge clarity and vivid detail without an additional flattener, making it perfect for capturing expansive celestial views. Its robust build, exceptional optics, and innovative features redefine the standard for astrophotography.

Key Features:

Advanced 5-Element Petzval Design
Eliminates field curvature, providing sharp, flat-field images without requiring additional flatteners.

50mm Image Circle
Fully supports full-frame and medium-format cameras for wide-field and detailed astrophotography.

F/4.8 Fast Optics
Offers exceptional light-gathering capability for vibrant deep-sky photography.

WIFD (William’s Internal Focuser Design)
Patented internal focuser ensures precise, stable, and hassle-free imaging, avoiding balance issues and eliminating vignetting. Zero image shift!

Anti-Shrink Lens Cell Technology
Minimizes thermal expansion and contraction, maintaining perfect optical alignment in any environment.

Sensor Tilt Xterminator
Integrated and patented design eliminates distortion, optimizing sharpness and detail for professional-level results.

Built-In Patented Bahtinov Mask in Front Cap
Simplifies focusing for pinpoint precision, a feature that sets it apart from competitors.

Patented Handle Bar Design
Combines ergonomic usability with enhanced portability.

UltraCat 56 Specifications...

• Lens Type: 5-Element Advanced Petzval

• Focal Length: 269 mm

• Lens Diameter: 56 mm

• Focal Ratio: f/4.8

• Focuser: WIFD Rack & Pinion, compatible with EAF, 0-30mm focus travel

• Adapters Included: Sensor Tilt Corrector/Rotator, M68 to M48 Camera Adapter

• Optional Flattener? No flattener required due to inherent flat field of this five-element Petzval scope. Backspacing calculations are a thing of the past as well! As long as your camera can reach focus, the entire frame will, too. You'll love the ease of set up and quality of the images!

• Camera Format: Full Frame, APS-C, M 4/3, Medium Format

• Tube Length (minimum and maximum): 11.7" retracted, 12.7" extended

• OTA Weight: 2.56 kg

What's in the Box?

• UltraCat 56 OTA

• Sensor Tilt Xterminator with integrated Rotator

• M68 to M48 Adapter

• Rear Dust Cap

• Objective Cap with Bahtinov Mask for help with focusing

• Temperature Gauge built into coarse focus knob

• Handle Bar with top Vixen-Style dovetail for guidescope

• 210mm Dovetail Plate - Two sided, Vixen & Arca-Swiss

• Allen Keys