Last night, in addition to debuting three lenses everybody knew were coming, Sigma revealed something nobody saw coming: the L-mount Sigma fp, “the world’s smallest and lightest ‘pocketable full-frame’ camera.” We’ve known Sigma was working on an L-mount camera ever since the announcement of the L-mount Alliance, but the Sigma fp has taken everybody by surprise. Unbelievably lightweight and compact, the camera measures in at 112.6 × 69.9 × 45.3mm and weighs just 370g (422g with the battery and SD…