Internal focus, smooth and easy. Beautiful balance for hand holding as long as you use fast shutter speeds. Rarely shoot this under 1/1600, but possible at 1/800 while tracking. Generally try and hit ISO 200-400 @ 1/3200 - 1/4000. Always used wide open on the NEX-7. Manual focus and its really my walk about lens this one. Length x max. diameter: 395mm x 128mm Weight: 2,610g All the best. Danny.