Metabones EF-MFT Lens Adapater

As if the Panasonic GH4 wasn’t making enough waves in the prosumer 4K market, Metabones has released a Speed Booster EF to MFT adapter capable of reducing the GH4’s crop factor to match the field of view of a Super 35 camera.

Panasonic’s GH4 Micro four-thirds sensor DSLR, while very capable, has a native crop of 2.3x when shooting in 4K and 2.0x when shooting in 1080p. The reduction in crop and an increase in light means a sharper, brighter and wider image.

According to Metabones, “In 4K mode on the GH4 we end up somewhere between 1.7x and 1.8x crop depending on the type of 4K resolution selected. The 4096 x 2160 DCI 1.85:1 mode of course uses more of the sensor area to record the image thus the crop factor is a little less. In stills mode and with the internal 1080p recording the crop factor with Speed Booster is 1.5x, or actually in cinematography terms a 1.0x because it is Super 35mm.”

Some of the key features of the Metabones Canon EF to MFT adapter (or Nikon equivalent) are:

A full stop increase to maximum aperture
Increased lens MTF (Modulation Transfer Function – a measure of image detail)
Reduced crop – it makes lenses 0.71x wider
Built-in electronics to control lens aperture
Powered by camera body OR by a MicroUSB socket (third party power supply required)
High performance 32-bit processor and efficient switched mode power supply
Detachable tripod foot, compatible with Arca Swiss, Markins and Photo Clam ball heads

The Speed Booster is available now through the Metabones website, alongside Metabones brethren, the EF to MFT Smart Adapter, for $599 and $399, respectively.

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Russ Fairley
Russ Fairley is a producer, editor and motion graphic designer who enjoys writing for Videomaker. He has also written for (, RedShark News, Modern Drummer Magazine, and others. He is an Adobe Certified Expert, Adobe Community Leader, and co-founder of After Effects Toronto, Canada's largest motion graphic user group. Fairley is the creator and editor of, a popular production news website.