The GH4 is an awesome camera by itself but adding a Metabones speedbooster with the Sigma 18-35mm f1.8 lens turns the GH4 into a full frame beating monster offering shallow depth of field as well as great low light performance from this smaller sensor camera. Take a look to see how it is done and if it is worth it.
Purchase the Metabones:
Nikon Mount: [ Ссылка ]
Canon Mount: [ Ссылка ]
