The Tamron 70-180mm f/2.8 Di III VC VXD G2 is an unusual lens: a constant-aperture telephoto zoom for Sony E-mount that weighs 855 grams — roughly half the weight of the Sony FE 70-200mm f/2.8 G Master II. For handheld video work, that weight difference is not a specification point. It is the difference between a take you hold for ninety seconds and one you abandon at forty. The G2 version adds VC — Vibration Compensation — to the optical formula, and on a Sony body with sensor-based IBIS (A7 IV, A7R V, ZV-E1), the combined stabilization produces five to six stops of effective compensation at the telephoto end.