William Optics UltraCat 56 WIFD f/4.8 + FREE International Shipping

Highlights of the Ultra-CAT 56 WIFD APO

• 5 elements Petzval flat field design with FPL-53 optics
• WO Internal Focus Design (WIFD), compatible with motorised focuser
• Fast focal ratio f/4.8
• Full frame format coverage (50mm)
• Anti-Shrink Lens Cell Technology
• Sensor Tilt eXterminator (STX)
• Interchangeable camera mount (Canon EF, RF / Nikon F,Z / Sony E / Pentax K / M4/3 / Fujifilm X)
• Compatible with any 48mm (2") imaging filter
• Super bright Bahtinov mask + lens cap
• Field rotator 
• 3.2kg only including mounting base (OTA only 2.56kg)

Exclusive features of the Ultra-CAT 56 WIFD APO:

• Sensor Tilt Corrector (STX)
• Full frame format coverage
• WO patented innovative internal focus design (WIFD)

Package Includes:

1. UltraCAT 56 APO WIFD
2. WO lens cap with bahtinov Mask 
3. Mounting rings with Saddle Handle Bar
4. Camera Angle Rotator
5. Sensor Tilt eXterminator (STX)
6. Vixen Style Dovetail Plate
7. M48 and M54 adapters
8. Soft carrying case
9. Allen key set 

 Optical Diagrams

Spot Diagram

Longitudinal Aberration 

William Optics Ultra-Cat 56 Specifications