The Sigma 18-35mm f/1.8 DC HSM A1 is a high quality zoom lens designed specifically for crop-frame Canon EF-mount cameras. Key features include:

Fast f/1.8 Aperture Zoom: While most zoom lens apertures top off at f/2.8, the Sigma 18-35mm bests that by 1 1/3-stops. This enables stellar low light shooting, as well as providing full-frame like depth-of-field on a crop-frame camera.

Wide to Normal Range: With a 35mm-equivalent focal length of 29mm-56mm, it covers your wide to normal range. This makes it a great option for landscape, event, and street photographers.

High Build and Image Quality: As a member of Sigma’s Art lens line, it goes through Sigma’s rigorous A1 testing, ensuring high image quality. Optically, four aspherical and five SLD glass elements are used to minimize distortion and aberrations throughout the zoom range, with Super Multi-Layer coatings for eliminating lens flare and ghosting. The barrel is made of a lightweight TSC compound that gives the lens a solid, sturdy feel. Internal focusing and zooming further back this claim.

Dock-Compatible: This lens is also compatible with the Sigma USB Dock for Canon EF Lenses (separate rental item) which allows users to specify certain parameters like fine-tuning microfocus through the Sigma Optimization Pro software.