The Metabones Canon EF Lens to RF-mount T Speed Booster ULTRA 0.71x (MB_SPEF-EFR-BT1) adapts full-frame Canon EF lenses to RF-mount cameras. It makes the lens 0.71x wider and adds one stop of maximum aperture, to a maximum output of f/0.9.

Metabones lists APS-C and Super 35 bodies such as the EOS R7, R10, R50 and C70. Full-frame RF bodies work in APS-C crop mode only. EF-S lenses do not fit.

Key Features

• Optics: Five-element, four-group design with ultra-high index tantalum-based glass by Caldwell Photographic
• Magnification: 0.71x, adds 1 stop, maximum output aperture f/0.9
• Autofocus: Dual-pixel AF and video AF support; IS lens support
• Control wheel: Built-in wheel assignable to ISO, shutter speed, aperture or depth-of-field preview
• Power: Powered by the camera body; no external power with most lenses
• Build: Aluminum alloy and brass, chromium plated, rubber gasket at the RF mount
• Tripod foot: Detachable, fits Arca Swiss, Markins and Photo Clam heads

Specifications

Frequently Asked Questions

Do EF-S lenses work?
No. EF-S and APS-C lenses do not fit or cover the image circle.

Which cameras does it support?
EOS C70, R7, R10 and R50, plus full-frame RF bodies in APS-C crop mode, and RED Komodo 6K and Komodo-X.

Does autofocus work?
Yes. Metabones lists dual-pixel AF, video AF and IS lens support.

What does a 50mm f/1.2 become?
Metabones gives a 35.5mm f/0.9 equivalent.

Do I need a battery?
No. The adapter is powered by the camera body with most lenses.

Is this genuine Metabones?
100% genuine, warranty-backed, delivered across India.

Shipping & Delivery

We aim to deliver your order quickly and safely across India.

• Orders are usually processed within 24–48 hours (excluding Sundays & holidays)
• Once shipped, delivery typically takes 2–7 business days, depending on your location
• You will receive a tracking link via SMS/email once your order is dispatched
  

Shipping Charges

• Shipping charges (if applicable) will be displayed at checkout
• Free shipping may be available on select products or order values
  

Order Tracking

• Track your order anytime using the link shared after dispatch
• For any assistance, feel free to contact our support team
  

Important Notes

• Delivery timelines may vary due to courier delays, weather, or unforeseen circumstances
• Ensure your address and contact details are accurate to avoid delays
• We currently ship only within India

Easy 7-Day Support

We offer 7-day support from the date of delivery in case of:

• Damaged product on arrival
• Manufacturing defects
• Incorrect item received
  

Conditions for Return/Replacement

To be eligible:

• Product must be unused and in original condition
• Must include original packaging, accessories, and invoice
• Issue must be reported within 7 days of delivery
  

Non-Returnable Items

• Used or physically damaged products
• Products without original packaging
• Items damaged due to misuse
  

How to Request

• Contact us via email or phone with your order ID and issue details
• Share images/videos if required for faster resolution
• Our team will guide you through the next steps
  

Refunds (if applicable)

• Refunds are processed after product inspection
• Amount will be credited to the original payment method within 5–7 business days