The A mount Zeiss 50/1.4 SSM weighs same (and is more compact). Moreover the Contax Planar 50/1.4 weighs 290g. That we praise weight of the new lens shows how large mirrorless lenses had gotten from both Sony and Sigma. The new generation GMs are definitely trying to rectify that, but let’s give credit to light handling offered in the SLR/DSLR/SLT era!!