Spanning an impressive wide-angle to super-telephoto range, the Canon EF-mount 18-400mm f/3.5-6.3 Di II VC HLD from Tamron is a true all-in-one lens to suit photographing the widest of vistas to the details of wildlife. Designed for APS-C-format DSLRs, this 28.8-640mm equivalent lens uses a three-step extension design to maintain a compact and lightweight form factor despite its expansive reach. In regard to the optics, a series of aspherical and low dispersion elements help to correct various aberrations and distortion for consistent sharpness and clarity throughout the zoom range.