The new Speed Booster ULTRA 0.71x for BMPCC4K uses an advanced 6-element 4-group optical design incorporating ultra-high index tantalum-based optical glass.  The new design is specifically optimized to bring the same level of astonishing performance as the ULTRA Speed Boosters for Micro Four Thirds to users of the Blackmagic Pocket Cinema Camera 4K.

In particular, the Speed Booster ULTRA 0.71x is optimized to correctly account for the BMPCC4K camera’s specific 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, an enormous range of full-frame optics, ranging from vintage film lenses to the latest digital designs, will function flawlessly when adapted to BMPCC4K bodies.

The Speed Booster ULTRA 0.71x reduces the crop factor of the BMPCC4K camera as shown in the table below. The new design for BMPCC4K 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 full-frame SLR lenses regardless of aperture or exit pupil distance.  The Speed Booster ULTRA 0.71x will also work extremely well with many DX and APS-C format lenses provided the image circle provided by the lens is large enough. The 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 0.71x.

The BMPCC4K Speed Booster ULTRA 0.71x reduces the crop factor of the BMPCC 4K camera from 2.02x to 1.43x and produces the largest aperture optics currently available, with a maximum output aperture of f/0.9. 

This new series of Metabones Speed Booster adapters is designed exclusively for Blackmagic Design Pocket Cinema Camera 4K (BMPCC4K). They cannot be attached to any other m43 cameras such as JVC, Olympus or Panasonic cameras.

In a nutshell, we recommend XL for full-frame lenses and ULTRA for DX/APS-C lenses. 

* Calculations based on the width of the sensor in relation to a full-frame sensor.