We really didn’t know what to expect going into this. Panasonic hasn’t even made an APS-C body before, never mind a full-frame flagship mirrorless camera. Though, it seems they realized the S1 series needed to make a splash if its release was going to trail behind Canon and Nikon’s first foray into professional-grade mirrorless cameras, because the S1R is massive. This body is titanic compared to its competitors: the A7R III, Z7, and EOS R. Panasonic has decisively abandoned the…