Metabones Announces Speed Booster ULTRA 0.71x for Micro Four Thirds Cameras

Metabones has announced a new Speed Booster ULTRA series of focal reducing adapter designed for Micro Four Thirds mirrorless cameras.

The Speed Booster ULTRA 0.71x has a magnification of 0.71x, and so it effectively reduces the crop factor of mirrorless Micro Four Thirds mount cameras from 2.0x to 1.4x.

The new Speed Booster ULTRA m43 uses an advanced 5-element 4-group optical design incorporating ultra-high index tantalum-based optical glass. The new design optimized for the Micro Four Thirds sensor and filter stack, and as a result achieves an astonishing level of performance that sets a new standard for focal reducers.

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Metabones Speed Booster ULTRA 0.71x M43 Mirrorless Camera Press Release

Petersburg, VA, USA, July 24, 2015:  Caldwell Photographic Inc. and Metabones® are pleased to announce a new Speed Booster ULTRA series of focal reducing adapters designed for Micro Four Thirds mirrorless cameras.  Like the ULTRA series for Sony E-mount, the new Speed Booster ULTRA m43 uses an advanced 5-element 4-group optical design incorporating ultra-high index tantalum-based optical glass.  However, the new design is specifically optimized for the Micro Four Thirds sensor and filter stack, and as a result achieves an astonishing level of performance that sets a new standard for focal reducers.

Like the revolutionary original Metabones Speed Booster® announced in January 2013, the Speed Booster ULTRA m43 has a magnification of 0.71x, and so it effectively reduces the crop factor of mirrorless Micro Four Thirds mount cameras from 2.0x to 1.4x.  However, the new ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is almost perfectly corrected for use with all fullframe SLR lenses regardless of aperture.  The Speed Booster ULTRA m43 will also work extremely well with many DX and APS-C format lenses provided the image circle of the lens is large enough.  Optical performance of the new Speed Boosters is so good that the MTF of any lens attached to it will be improved.  Even the latest generation of ultra-high performance SLR lenses such as the Zeiss Otus series can be improved by adding a Speed Booster ULTRA m43.

Figures 2 through 4 below show MTF at 10, 20, and 40 lp/mm as a function of image height for output apertures of f/0.9, f/1.0, and f/2.0, respectively1.   At the maximum aperture of f/0.90 (i.e., with an f/1.2 master lens) the sharpness and contrast are extraordinary across the entire image circle.  At just one-third stop down to f/1.0 the performance is equal to or better than the best photographic lenses used at their optimum apertures.  An additional stop down to f/2.0 yields performance that is rarely encountered in photographic optics.  In practice, what all of this means is that the new Speed Boosters will always enhance and never degrade the performance of the attached master lens.

And other aspects of optical performance haven’t been sacrificed in order to obtain high MTF, either.  Figure 5 shows that there is less than 1 stop of corner illumination falloff even wide-open at f/0.9. There is no vignetting at all after the output aperture reaches f/2.82.  Figure 6 shows that rectilinear distortion added by the Speed Booster ULTRA m43 is negligible at less than 0.7%. The charts shown in Figures 2 through 6 below show the optical performance of the Speed Booster ULTRA m43 when mounted behind an ideal “perfect” lens.

Like all Metabones Speed Boosters, the Speed Booster ULTRA m43 is optimized to correctly account for the camera’s filter stack located near the sensor surface3.  This is especially critical at the extremely large apertures made possible by Speed Booster technology.  As a result of this careful optimization, an enormous range of full-frame optics, ranging from vintage film lenses to the latest digital designs, will function flawlessly when adapted to Micro Four Thirds camera bodies.

Metabones Speed Booster ULTRA m43 Specifications: 

  • Model Code:  MB_SPEF-m43-BT4 (Canon EF mount), MB_SPNFG-m43-BM3 (Nikon F/G mount)
  • Color: Black Satin exterior; Black Matte interior
  • Magnification:  0.71x
  • Crop Factor for Full Micro Four Thirds format:  1.42x
  • Crop Factor with GH4 in Cinema 4k (4096 x 2160) Video Mode:  1.66x
  • Maximum Output Aperture:  f/0.90 (with f/1.2 lens attached)
  • Rectilinear Distortion:  < 0.7%
  • Lens Elements/Groups:  5/4
  • Length Reduction:  5.5 mm
  • Camera Mount:  Micro Four Thirds
  • Compatibility:  All Micro Four Thirds cameras are supported
  • Image Format:  17.3 mm x 13.0 mm (full Micro Four Thirds format)
  • Lens Mounts:  Canon EF and Nikon F/G at release; other mounts to follow in the near future
  • Lens Compatibility:  Any full-frame (36 mm x 24 mm format) SLR lens with the appropriate mount can be used.  DX format lenses can be mounted but may result in vignetting when the full Micro Four Thirds format is used, depending on the lens.  DX lenses are fully supported when used on the Panasonic GH4 in Cinema 4k mode, and will function without abnormal vignetting.  Canon EF-S lenses are not supported, but third-party EF-mount APS-C lenses can be mounted and will have full electronic functionality.

See more details at Metabones website.