HANDS ON: Like Sigma's earlier version, this lens is large (over 10 inches long, with hood) and heavy (more than 3 pounds). Surfaced with a pro-black, hard-coated, baked-on, crinkle finish, it feels sturdy and very well constructed. The manual focus collar spins smoothly, with a long turning radius that enables very fine manual focusing. The zoom ring turns stiffly, but it will probably loosen with use. Its AF action, in the Canon mount, is fast and very quiet, thanks to Sigma's Hyper Sonic Motor (HSM).