William Optics Apochromatic Refractor AP 76/365 UltraCat WIFD

William Optics Apochromatic Refractor AP 76/365 UltraCat WIFD

With a 5-element advanced Petzval optical design, including super ED and lanthanum glass, and a fast f/4.8 focal ratio, this telescope delivers stunningly sharp, flat-field images across its 50mm image circle. Optimized for Full Frame, APS-C, and M4/3 sensors, it also offers compatibility with Medium Format cameras for outstanding wide-field astrophotography.

The UltraCat astrograph at a glance

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 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 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.

Safety informations: PDF Download