Metabones Canon EF to Canon EFR T Speed Booster ULTRA 0.71x Adapter (Black) - With Tripod Foot (EOS R)

Canon EF Lens to RF-mount T Speed Booster ULTRA 0.71x — Cinema-Grade Full-Frame Optics on Super35 Sensors

This professional-grade optical adapter converts full-frame Canon EF-mount lenses for use on Canon RF-mount cameras, reducing the crop factor by 0.71x while increasing the maximum aperture by a full stop.

Maximizing Commercial Production Value

In high-stakes commercial environments, visual consistency across multi-camera setups is paramount. This adapter leverages an advanced 5-element in 4-group optical path engineered by Caldwell Photographic, incorporating ultra-high index tantalum-based glass. This exotic configuration ensures maximum modulation transfer function metrics, drastically reducing the edge distortion and peripheral vignetting that can compromise adapted glass. By transforming standard f/2.8 zooms into high-speed f/2.0 assets, production houses can extract peak performance from existing lens investments while maintaining pristine corner-to-corner resolution for discerning clients.

Furthermore, seamless integration into modern cinema ecosystems is guaranteed via rigorous electronic translation. The hardware facilitates uninterrupted communication between the lens and advanced camera systems such as the Canon EOS C70, RED KOMODO 6K, and RED KOMODO-X. Dual-pixel autofocus tracking and internal image stabilization protocols operate with absolute fidelity, providing operators with the rock-solid reliability needed for fast-paced commercial workflows where a single missed focus pull can compromise an entire day's production budget.

The structural housing matches this electronic precision, utilizing precision-machined aluminum alloy and brass elements finished with chromium plating. An interior flocked treatment absorbs stray light rays to mitigate internal reflections, preserving native lens contrast under intense studio lighting arrays. A robust rubber gasket at the mount interface safeguards the electronic connections against environmental ingress, ensuring stable, uninterrupted operation during demanding commercial shooting schedules.

Critical Performance Benchmarks

• Optical Magnification: 0.71x

• Aperture Gain: Increases maximum lens aperture by 1 stop (up to a maximum output of f/0.9)

• Optical Construction: 5 elements in 4 groups utilizing ultra-high index tantalum-based optical glass

• Camera Mount Compatibility: Canon RF-mount (specifically optimized for APS-C / Super35 formats like EOS C70, RED KOMODO 6K, KOMODO-X, and full-frame bodies in crop mode)

• Lens Mount Compatibility: Canon EF-mount full-frame lenses (not compatible with EF-S or third-party APS-C lenses)

• Electronic Integration: Supports Dual-Pixel Autofocus (DPAF), Video AF, Image Stabilization (IS), and cinema lens control (e.g., Canon CN-E 18-80mm T4.4 L)

• EXIF Metadata Capture: Generates real-time focal length, aperture, and lens identification metadata

• Control Interface: Built-in multi-function programmable Control Wheel (rotary and push-in selection) for assignable parameters such as aperture, ISO, or shutter speed

• Internal Reflection Management: Deep internal flocking to minimize glare and maximize contrast

• Weather Sealing: Integrated rubber gasket at the camera-side RF mount interface

• Mechanical Build: Heavy-duty aluminum alloy and brass construction with durable chromium plating and a premium satin exterior finish

• Tripod Support: Detachable footprint compatible with Arca-Swiss, Markins, and Photo Clam ball head quick-release systems

• Power Delivery: Maintained directly via the host camera body interface; no external auxiliary power source required for standard operation

• Dimensions: 28.1 x 73.0 x 77.2 mm

• Weight: 198 grams

Integration & Deployment FAQ

Q: How does this adapter assist in matching color and contrast characteristics in a multi-camera commercial studio environment?

A: The optical element incorporates specialized coatings and tantalum glass elements designed to remain completely neutral across the visible spectrum. Because it does not induce color shifting, the baseline color metrics of your EF-mount glass are preserved identically. This prevents color imbalances when mixing adapted lenses alongside native RF glass on an identical sensor matrix.

Q: Can this system be deployed safely with specialized cinema lenses like the Canon CN-E servo zoom series?

A: Yes. The electronic firmware maps the communication lines perfectly to support advanced cinema setups like the CN-E 18-80mm T4.4 L servo zoom when mounted on compatible cinema bodies. Servo zoom controls, electronic iris mapping, and comprehensive metadata logging flow smoothly through the internal data pipeline.

Q: Is there a built-in mechanism to handle metadata management when employing vintage mechanical manual lenses?

A: The hardware features an integrated chip emulation function capable of storing specific lens identification, focal length, and aperture profiles for a completely passive manual lens. This profile can be customized via desktop application tools and toggled on set by depressing the integrated multi-function control wheel.

Q: What operational step must be taken regarding in-camera software lens corrections during configuration?

A: Because the optical elements reshape the image circle to maximize illumination and sharpness, native digital aberration corrections within the camera menu must be disabled. The adapter passes an internal protocol instructing the camera to turn off automatic peripheral illumination and chromatic aberration corrections to prevent artificial digital artifacting over the optically optimized image.