A versatile telephoto zoom lens, the Canon EF-mount 100-400mm f/4.5-6.3 Di VC USD from Tamron offers a useful focal length range in a lightweight design. Designed for use with full-frame Canon EF-mount DSLRs, it can also be used with APS-C models where it will provide a 160-640mm equivalent focal length range. The lens uses a 17 elements in 11 groups optical design that incorporates three LD (low dispersion) elements to reduce colour fringing and chromatic aberrations, while an eBAND coating has been applied to individual elements to reduce lens flare and ghosting for improved contrast and clarity when working in backlit conditions. Complementing the optical design is a high-speed Ultrasonic Silent Drive (USD) autofocus system, which is benefitted by a dual Micro-Processing Unit (MPU) control system for quick and responsive performance. Together, they meet a CIPA image stabilisation performance level of 4 stops to minimise the appearance of camera shake for sharper handheld shooting. This motor also affords full-time manual focus control, and it is possible to focus on subjects as close as 1.49 metres away. The lens is finished with a dust- and moisture-resistant magnesium alloy construction that is weather-sealed for working in changeable environmental conditions, and a fluorine coating has also been applied to the front lens element to protect against dust, dirt, and smudges. An optional removable rotating tripod collar is available, which features an Arca-type compatible foot and benefits working with the lens atop a tripod or monopod. The 100-400mm f/4.5-6.3 Di VC USD supports working with the optional Teleconverter 1.4x to further extend the effective focal length range to 140-560mm, and it is compatible with optional TAP-in Console for fine-tuning select focusing adjustments and for updating lens firmware.
