Sigma has introduced the MC-21 mount converter for mirrorless L-mount bodies, at the time of writing which includes the Leica SL/TL and the new Panasonic S1 and S1R. There are two versions of the converter, the £249.99 EF-L allows Canon EF mount lenses, including Sigma lenses with EF mount to attach to L mount bodies. Priced at just £99, the SA-L version allows Sigma lenses with the SA mount to fit the same bodies. Sigma has confirmed the new converter has compatibility with 29 Sigma full-frame and APS-C lenses with the latter automatically enabling the auto-crop feature on full-frame bodies. Other models are not guaranteed as being fully compatible. Lens…