William Optics Ultra-Cat 108 WIFD Apo f/4.8

The William Optics UltraCat 108 is a cutting-edge 108mm 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, it delivers breathtaking edge-to-edge clarity and vivid detail, making it perfect for capturing expansive celestial views. Its robust build, exceptional optics, and innovative features redefine the standard for astrophotography.

The Petzval optical design includes two Super ED glass lenses, one ED glass lens, and lanthanum lenses with advanced fully multi-coated coatings. Together, they deliver sharp, vibrant images with true-to-life colours and significantly reduced chromatic aberration.

Key Features:

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

60mm Superior Image Circle
Fully supports full-frame and medium-format cameras for wide-field and detailed astrophotography, outperforming standard 106mm telescopes.

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.

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

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

Built-In Patented Bahtinov Mask
Simplifies focusing for pinpoint precision, a feature that differentiates it from competitors.

Patented Handle Bar Design
Combines ergonomic usability with enhanced portability.

Specification: 

Lens Type:  5-Element Advanced Petzval
Lens Elements:  Two Super ED glass lenses, one ED glass lens, and lanthanum lenses
Focal Length:  518 mm
Diameter:  108 mm
Focal Ratio:  f/4.8
Image circle:  60 mm
Focuser:  WIFD R&P Focuser Compatible with EAF
Focus travel:  0-30 mm (Ruler to 31mm)
Adapter Included:  Sensor Tilt Xterminator Rotator M68, 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, Full Frame, APS-C & M4/3
Tube Length:  512.9 mm - 617.9 mm
OTA Weight:  7.82 kg / 17.24 lbs

What's in the box

• William Optics Ultra-Cat 108
• Bahtinov Focusing Cap
• M48, M54, M68 Adapters
• Tube Rings
• Carry Handle
• Vixen Style Mounting Plate
• Allen Key set
• Soft Carry Case