Mounted on a D7000, the sharpness is the appointment. I could compare it to the Nikon 70-200 FY ... it's slower it's on ... but if you start from scratch ... if you have a little distance from it will focus very quickly. Tested gym provided light and he is well out! Piqué super close to the Nikon 70-200 ... well on the Nikon does better but the price is almost multiplied by 5. The stabilization is not present, but if you do not need to photograph below 1/200, it is useless, or it must use a monopod ....