Compare Olympus M.Zuiko Digital ED 100-400mm f 5-6.3 IS Lens vs OM SYSTEM M. Zuiko 150-400mm f 4.5 TC 1.25 IS PRO Lens vs Panasonic Leica DG Vario-Elmar 100-400mm f 4-6.3 II ASPH. POWER O.I.S. Lens