Metabones SPEF-M43-BT4 Canon EF to MFT lens mount adapter

Canon EF lens adapter to MFT camera bodies. Speed Booster ULTRA M43 uses an advanced 5-element, 4-group optical design that incorporates an ultra-high index tantalum-based optical glass, is specifically optimized for the Micro Four Thirds sensor and filter range, and as a result achieves an amazing level of performance that sets a new standard for focal reducers.

It has a magnification of 0.71x, effectively reducing the cutting factor of Micro Four Thirds mirrorless mounting cameras from 2.0x to 1.4x. However, the new ULTRA design makes very effective use of exotic materials at the far end of glass manufacturing technology and, as a result, is almost perfectly corrected for use with all full frame SLR lenses, regardless of aperture. It will also work very well with many DX and APS-C format lenses as long as the image circle of the lens is large enough. Even the latest generation of ultra high-performance SLR lenses such as the Zeiss Otus series can be enhanced by adding a Speed Booster ULTRA M43.

What is new in the Speed Booster ULTRA for mounting Canon EF on Micro Four Thirds is the autofocus support, subject to certain limitations. The bodies of the Panasonic Micro Four Thirds cameras are able to precisely autofocus even if the maximum aperture of the Speed Booster and the combined lens is in the sub-f/1.0 range.

Both the camera side and the lens side of the adapter are made of precision machined, chrome plated brass. Precise fit and solid connection with no lens slack, holes or jolts when mounted on the adapter and no adjustments are required to adapt it to your lens.

Designed to achieve infinite focus while maintaining the correct registration distance needed to maintain the optical quality of CRC lenses or floating element lenses.

  
Metabones SPEF-M43-BT4 lens adapter features

• Optical
  • Increase maximum aperture by 1 stop
  • Increase MTF of any lens attached
  • Makes lens 0.71x wider
  • Patented 5-element/4-group optical design incorporating ultra-high index tantalum-based optical glass by Caldwell Photographic in the USA
  • Supports 16:9 video with DX lenses
       
• Electronic
  • Autofocus
  • Can be powered either by camera body or by third-party external 5V power source (not included)
  • Iris/aperture controlled by the camera body
  • Smooth iris support with the latest Canon (2009+), Tamron (SP series 2013+) and Sigma (2016+) lenses
  • Image stabilization (IS) lens support
  • Support for cameras with in-body image stabilization (IBIS), including Panasonic GX7, GX8, GX80/85 and Olympus cameras
  • Electronic manual focusing (e.g. EF 85/1.2L II and discontinued EF 50/1.0L)
  • EXIF (focal length, aperture, zoom range)
  • Distance and zoom display on camcorders (requires lenses supporting distance information)
  • Cinema EOS lens support (CN-E 18-80mm T4.4 L), including AF (requires external 5V power via micro USB port), auto iris and servo zoom
      
• Other
  • Detachable tripod foot compatible with Arca Swiss, Markins and Photo Clam ball heads
  • The opening is flocked with felt material to reduce internal reflection
  • Compatible with all MFT mount cameras, including GH4, OM-D, Blackmagic Cinema Camera, Blackmagic Pocket Cinema Camera and JVC GY-LS300