The Sigma 18-35mm f/1.8 DC HSM Lens for Canon is a wide-angle to
normal-length zoom lens that features a fast, bright constant f/1.8
maximum aperture. It is specifically designed for use with APS-C-sized
sensors and provides a 35mm-equivalent focal length range of 28.8-56mm.
The lens integrates four aspherical elements into its construction as
well as five Special Low Dispersion (SLD) glass elements to help
minimize various aberrations and distortions throughout the zoom range
as well as provide greater image sharpness and clarity. A Super
Multi-Layer Coating has also been applied to lens elements to reduce
surface reflections, lens flare, and ghosting to produce images with
higher contrast and color fidelity. The lens barrel design is
constructed from a Thermally Stable Composite (TSC) material that is
akin to metal in texture and resistance to temperature and environmental
changes while also remaining lightweight and compact. An internal
focusing and zooming mechanism also helps to maintain a compact and
consistent overall length and non-rotating front ring also better
enables the use of circular polarizing filters. For control of focus, a
Hyper Sonic Motor (HSM) is used to ensure fast, precise, and quiet
focusing capabilities that are well suited to continuous shooting and
movie recording.
For updating lens firmware and fine-tuning its
nuances to best suit your personal shooting, this lens is compatible
with the Sigma USB Dock. The dock allows you to specify certain
parameters and other settings through the Sigma Optimization Pro
software, such as AF speed and focusing limitations.
