Ultra-Cat 56

Description

The Ultra-Cat 56 is a high-performance 56mm apochromatic refractor, engineered for astrophotographers who demand exceptional portability without sacrificing optical precision, color accuracy, and wide-field performance.

Featuring a 5-element advanced Petzval optical design with super ED and lanthanum glass, paired with a fast f/4.8 focal ratio, the Ultra-Cat 56 delivers razor-sharp, perfectly flat images across a 50mm image circle. With a 269mm focal length, it is optimized for Full Frame, APS-C, and M4/3 sensors, and remains fully compatible with Medium Format cameras, making it an ideal ultra-wide-field imaging platform for deep-sky and large-scale nebula photography.

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 Optics Internal Focuser Design)
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