Designed specifically for DSLR cameras with 'APS-C sized' imagers, Tamron's latest ultra-zoom lens, the AF18-270mm Di-II claims to offer the world's largest zoom ratio of any current lens. The 15x zoom covers angles of view that range from the equivalent to a 28mm wide angle to a 419mm ultra telephoto in 35mm format. As such, it represents a genuine 'all-purpose' lens for DSLR users who wish to cover as wide a variety of subjects as possible without having to change lenses.
Naturally, if you want to shoot at high zoom magnifications you need some kind of image stabilisation. Tamron has equipped the new lens with an 'advanced' VC (vibration compensation) mechanism that it claims allows users to shoot with shutter speeds up to four EV steps slower than would otherwise be possible without stabilisation. It also provides more stable viewfinder images to make framing shots easier.
Anti-shake correction relies on three coils arranged in a tri-axial system, which drive a compensator lens electromagnetically via three steel balls that support the optical system. These rolling balls have very low friction and produce fast and silent correction of camera shake, delivering stabilised viewfinder images. This system enables the lens to be mechanically simpler and results in a very small and light DSLR lens for such a long focal length range.
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