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Metabones MB_SPCN-E-BT1 Contax N Lens to Sony E-mount T Speed Booster ULTRA 0.71x Adapter

code: MB_SPCN-E-BT1
  • £648.00
  • RRP: £676.50
Status | Usually dispatched within 24 hours


  • Contax N Lens to Sony E-Mount Body
  • For APS-C Cameras or APS-C Mode
  • Increases Angle of View by 0.71x
  • Increases Maximum Aperture by 1 Stop

Metabones MB_SPCN-E-BT1 (MB_SPCN/E/BT1, MB_SPCN_E_BT1, MB_SPCN-E/BT1, mb_spcn-e-bt1) Contax N Lens to Sony E-mount T Speed Booster ULTRA 0.71x Adapter

Owners of legendary Carl Zeiss optics in Contax N-Mount have long demanded a trusted migration path to mirrorless cameras. With the advent of Metabones® Contax N-Mount to Sony E-Mount Smart Adapter, the longing is over.

Built upon the foundation of Metabones' past success, phase-detection autofocus on A9, A7R Mark III, A7 Mark III, A7R Mark II, A7 Mark II, A6500 and A6300 not only offers pinpoint accuracy but also AF speed significantly surpassing the original Contax N series AF cameras. (Tailored to single-lens reflex cameras with a traditional phase-detection autofocus system, Contax N lenses are not compatible with contrast-detection autofocus mirrorless cameras such as A7S Mark II.)

Get a glimpse of the ergonomic experience of the original Contax N1 camera by using the lens' own aperture ring in aperture priority and manual exposure modes on A9, A7 series, A6500 and A6300. Fully automatic exposure and shutter priority are also available.

A customizable button on the adapter can be assigned to more than 50 different functions on an A9, A7 series, A6500 or A6300 camera, including depth-of-field preview. Putting that button on the hand-grip side would have matched a genuine Contax N camera, but since that would have been next to Sony's lens release button, we opted to place this customizable button on the other side of the adapter instead, right where the thumb of your left hand is.

The workmanship and attention to detail are evident from the signature Metabones design and the two electrical contacts carrying power, which are thicker in the same way as a genuine Contax N series autofocus camera. The inside of the adapter is flocked with felt to minimize internal reflection. A tripod foot compatible with Arca-Swiss style quick release is included.

Metabones has a proven track record of firmware stability and timely firmware support. Firmware is user-upgradable via the adapter's micro USB port.

Metabones adapters relay distance information from the lens to the camera body to enable full 5-axis in-body image stabilization of the A9, A7 Mark III series, A7 Mark II series and A6500. (The Contax 645 Makro-Planar 4/120 lens does not report distance information and supports only 3-axis in-body image stabilization.)

Contax made history by offering the world's first full-frame digital camera, Contax N-Digital, in 2002. All Contax products had been discontinued by 2005, leaving some of the finest autofocus optics ever made in search of a successor. None of these lenses feature optical image stabilization, and this is where the 5-axis in-body image stabilization (SteadyShot INSIDE) of Sony A9, A7 Mark III series, A7 Mark II series and A6500 comes in as a much-needed complement.

The heritage lives on, with the very same Carl Zeiss lenses from the dawn of full-frame digital photography now leveraging the latest and greatest mirrorless camera features and poised to benefit from further technological advances in the future.

Speed Booster® ULTRA

Speed Booster® ULTRA uses an advanced 5-element/4-group optical design by Caldwell Photographic Inc., incorporating ultra-high index tantalum-based optical glass to achieve extraordinary optical performance with improved corner sharpness, distortion and reduced vignetting. Speed Booster® ULTRA has a magnification of 0.71x,  effectively reducing the crop factor of APS-C cameras from 1.5x to 1.07x. The Speed Booster® ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is well corrected for use with virtually all full-frame SLR lenses regardless of exit pupil distance. Thus, the Speed Booster ULTRA performs extremely well with professional-grade f/2.8 zoom lenses such as the Carl Zeiss Vario-Sonnar T*2,8/17-35. Similarly, high-speed fixed focal length lenses such as the Carl Zeiss Planar T* 1,4/50 and Carl Zeiss Planar T* 1,4/85 will be transformed into f/1.0 lenses with excellent contrast and resolution from the center all the way to the edges of the image. Like all Metabones Speed Boosters, the Speed Booster ULTRA is optimized to fully account for the camera’s filter stack located near the sensor surface. This is especially critical at the extremely large apertures made possible by Speed Booster technology. As a result of this careful optimization, the complete range of Contax N and Contax 645 lenses will function flawlessly when adapted to Sony E-mount APS-C format camera bodies. (Speed Booster ULTRA cannot be used to adapt a Contax 645 lens to a full-frame E-Mount camera such as the A9 and the A7 series.)


  • Camera Mount: Sony E
  • Lens Mount: Contax N
  • Magnification: 0.71x
  • Optical Design: 5 Elements in 4 Groups


  • Material: Brass
  • Tripod Mounting Thread: 1/4"-20
  • Dimensions: H: 1.2 x W: 2.8 x D: 3.0" / H: 31.4 x W: 72.3 x D: 76.0 mm
  • Weight: 7.30 oz / 207 g

In the Box

  • Metabones Contax N Lens to Sony E-Mount T Speed Booster ULTRA 0.71x Adapter
  • Front and Rear Caps
  • Tripod Foot Hex Key
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