Metabones Contax Yashica CY to RF-mount CINE Speed Booster ULTRA 0.71x

The Metabones Contax Yashica CY to Canon RF Speed Booster ULTRA 0.71x CINE Adapter enables CY-mount lenses to be used on Canon RF-mount cameras while increasing light transmission and widening the field of view. Designed for professional cinema use, it features a robust positive-lock mechanism and advanced optics for superior image quality.

The Metabones Contax Yashica (CY) to Canon RF-mount Speed Booster ULTRA 0.71x CINE Adapter is a high-performance solution designed for filmmakers and photographers seeking to adapt classic CY-mount lenses to modern Canon RF-mount cameras. Built as part of Metabones’ professional CINE series, this adapter incorporates a rugged cine-style positive-lock mechanism that securely locks the lens in place, eliminating play and ensuring precise focus control—essential for demanding video production environments.

At its core is the renowned Speed Booster ULTRA optical system, featuring a sophisticated 5-element, 4-group design developed with ultra-high index tantalum-based optical glass by Caldwell Photographic. This advanced design reduces the effective focal length by 0.71x, resulting in a wider field of view while simultaneously increasing the maximum aperture by one stop. The result is brighter images, improved low-light performance, enhanced sharpness, reduced distortion, and minimized vignetting.

Constructed from a combination of aluminum alloy and precision-machined brass with durable chromium plating, the adapter offers exceptional durability and a premium satin finish that matches professional camera equipment. A built-in rubber gasket protects the RF mount from dust and moisture, making it suitable for use in various shooting conditions.

Additionally, the adapter includes a detachable Arca-type tripod foot, allowing direct compatibility with Arca-Swiss style tripod systems or attachment via a standard 1/4"-20 screw. Optimized for APS-C format cameras such as the Canon C70 and RED Komodo—or full-frame RF cameras in crop mode—this adapter expands creative possibilities while maintaining top-tier optical and mechanical performance.

Key Features

• Adapts Contax Yashica (CY) mount lenses to Canon RF-mount cameras
• Speed Booster ULTRA with 0.71x magnification
• Increases maximum aperture by approximately 1 stop
• Wider field of view with reduced crop factor
• Improves MTF, sharpness, and overall image quality
• Advanced 5-element / 4-group optical design
• Ultra-high index tantalum-based optical glass (Caldwell Photographic)
• CINE version with positive-lock lens mechanism (no play or movement)
• Durable aluminum alloy and brass construction with chromium plating
• Satin surface finish matching professional gear
• Rubber gasket for dust and moisture protection
• Detachable Arca-type tripod foot (Arca-Swiss compatible)
• Designed for APS-C cameras or crop mode on full-frame bodies