The Sigma 18-35mm f1.8 DC Art Series HSM lens in Canon mount integrates one aspherical element into its construction as well as Special Low Dispersion (SLD) glass 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. Also, 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.

Optimized Lens Design
One aspherical lens element, as well as the incorporation of SLD glass, help to minimize the appearance of distortions and aberrations throughout the zoom range and provide clear imagery with enhanced sharpness. A Super Multi-Layer Coating also benefits the image quality by reducing reflections and flare and contributing to greater overall contrast and fidelity. 

Hyper Sonic AF Motor
The Hyper Sonic Motor provides fast, quiet, and smooth auto focusing that is well-suited for use with video applications. This AF motor can also be manually overridden at any time by rotating the focusing ring, giving you the ability to fine-tune image sharpness through manual focusing. 

Art Lens Line
This lens is part of Sigma's Art line; deeming it well-suited to creative image making due to its large, constant f/1.8 maximum aperture and ability to produce aesthetic bokeh by way of a nine-blade circular diaphragm. The range of focal lengths it covers, from wide-angle to normal-length, is nicely situated for everyday and artistic shooting applications.