Sigma 28-105mm f2 .8 dg dn art £1,399/$1,499

LENS TEST

Zoom lens Sony FE 28-70mm F2 GM

Zoom lens Fujinon XF16-55mm F2.8 R LM WR II

£566/$699

LENS TEST

Sigma’s full-frame mirrorless camera is by far the most interesting camera of the year, but does it really make any sense? Andy Westlake finds out