This lens is an EF 16-35mmf/2.8L USM.
-Three types of aspherical elements.
-Highly resistant to dust and water droplets.
-Inner focusing and ring USM for silent and high-speed AF operation.
-Drop-in, gelatin filter holder provided at the rear.
-Circular diaphragm for better background blur.
To meet the growing demand of digital SLR owners, this ultra-wide-angle zoom offers a broader view, fast aperture, and closer focusing
Developed to succeed the high-performance 17-35mm f/2.8L USM, the EF 16-35mmf/2.8L USM has the leading wide-angle range in its class. Due to the proliferation of digital SLR Camera’s that tend to have a smaller frame size when compared to the 35mm,there is a demand for shorter focal length lenses, and this has resulted in the development of the EF 16-35mmf/2.8L USM. This is the first EF lens to have three types of aspherical elements (ground, replicated and Gmo [glass molded] which effectively correct the lens aberrations which occur during zooming. And despite its longer zoom range the EF16-35mm f/2.8L USM obtains a higher image quality than any other lens in its class.