I'd seen how popular the Metabones Speedbooster adaptors are, particularly among filmmakers, but knew very little of the real detail around this rather niche product.

Writing for the Hireacamera.com blog - a company that rents out theMetabones Speedbooster adaptors - I had an opportunity to write a guide and review from the perspective of a 'newbie'.

With the Sigma 18-35mm f/1.8 lens on a Panasonic GH4, an aperture of f/1.4 is used for this picture, which is made possible through the Metabones Speed Booster. Vignetting is obvious, but in this case looks rather good!

It was a fun time - receiving the Canon to Micro Four Thirds Metabones Speedbooster, a Canon fit 18-35mm f/1.8 Sigma lens for APS-C cameras and a Panasonic Lumix GH4 with which to use the adaptor.

There is much more detail in my two-part guide to Metabones adaptors on the hireacamera.com website, but in short the Metabones Speedbooster is the opposite of a teleconverter - decreasing focal length and increasing light intake.

My combination results in a 26-50mm f/1.2 lens for the GH4. It's quick to see why filmmakers with compact Micro Four Thirds cameras in particular love the adaptors so much.

The adaptors aren't perfect - there is a softness in edge detail at the wide aperture settings and AF is slower. However, centre sharpness is mightily impressive, with no discernible difference in images taken with the same lens yet without the adaptor.

Downsides but in perspective to what a Metabones Speed Booster offers - larger apertures from increased light intake and depth of field control for smaller format cameras - and the adaptors are a real winner.

For my in-depth Metabones adaptor guide, check out the hireacamera.com blog.

Detail is pin sharp when the lens is set to an optimum aperture