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Mechanical adapter for Leica R lenses to Canon RF APS-C cameras; 0.71x magnification, increases aperture by 1 stop, improves sharpness and reduces distortion.

Metabones Leica R to Canon RF Speed Booster ULTRA 0.71x (MB_SPLR-EFR-BM1)

Product ID: 51876
€ 629,95 tax incl.

Pre-order. Delivery time from 3 weeks.
SKU: 51876
Model: MB_SPLR-EFR-BM1
Ean: 4897050182949
Condition: New product
Manufacturer: Metabones
629.95
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Type of ProductAdapters for lens
Adapter is for lensesLeica R
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Metabones Leica R to Canon RF Speed Booster ULTRA 0.71x (MB_SPLR-EFR-BM1)

Metabones Leica R to Canon RF Speed Booster ULTRA 0.71x (MB_SPLR-EFR-BM1)

Mechanical adapter for Leica R lenses to Canon RF APS-C cameras; 0.71x magnification, increases aperture by 1 stop, improves sharpness and reduces distortion.

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Product details

Compatibility and Design

  • Adapter for Leica R-mount lenses to Canon RF-mount cameras.
  • Optimized for APS-C format cameras such as Canon C70, RED Komodo, or using APS-C crop mode on EOS R3, R5, R6, EOS R, and EOS RP.
  • Mechanical adapter without electronic aperture control, autofocus, or EXIF data transmission.

Optical Features

  • Advanced 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass manufactured by Caldwell Photographic, USA (patent granted).
  • Magnification factor of 0.71x, effectively making lenses wider and reducing crop factor.
  • Increases maximum aperture by 1 stop, enhancing light gathering capability.
  • Improves Modulation Transfer Function (MTF) for sharper images.
  • Delivers sharper corners, reduced distortion, and minimized vignetting.

Build and Finish

  • Constructed from precision-machined aluminum alloy and brass with chromium plating for durability and smooth mounting.
  • Satin surface finish matching OEM lens and camera mounts.
  • Detachable Arca-type tripod foot compatible with Arca Swiss, Markins, and Photo Clam ball heads; can clamp directly or attach via 1/4-20 screw to quick release plates.

Usage Notes and Limitations

  • Rear lens element must not protrude more than 10.5 mm from the flange.
  • Certain Leica R lenses require modification to fit safely: Super-Elmar-R 15mm, Elmarit R 28/2.8, Elmarit R 35/2.8, Summicron R 50/2.
  • Super telephoto lenses like Telyt 560/5.6 may cause corner vignetting.
  • Manual focus lenses with rear protrusions (spikes, levers) may damage the adapter and require modification before use.
  • Not compatible with Pentax K-mount lenses due to protruding fins and aperture levers.

Performance Highlights

The Speed Booster ULTRA transforms full-frame Leica R lenses for use on APS-C Canon RF cameras, effectively reducing the crop factor and increasing aperture speed. For example, a 50mm f/1.2 lens becomes approximately a 35.5mm f/0.9 lens with excellent contrast and resolution across the frame. It performs well with professional-grade f/2.8 zoom lenses, converting them into faster equivalents (e.g., 24-70mm f/2.8 to 17-50mm f/2.0).

Additional Information

  • Adapter ensures precise fit with no play or wobble, maintaining infinity focus and correct registration distance.
  • Internal matte-black treatment minimizes reflections to preserve optical quality.
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