HANDS ON: Somewhat smaller (zoomed out) than Tamron's comparable 15X 18-270mm VC optic, this attractive, matte-black lens is compact at 18mm, and notably light. The zoom action is very smooth for a lens that nearly doubles in length as it racks out. The AF action (on the Canon EOS 50D) is rapid and sure, even in low light, and the HSM motor delivers near-silent autofocus. Manual focus is well damped, but inoperable in the AF mode. Well marked with easyreading scales, the barrel also offers handy magnification ratios for its macro range.