Looking to take things up a notch, Canon's EF 16-35mm f/2.8L III USM
Lens embraces a revamped optical design with modern coating technologies
that promise improved outer and corner sharpness along with minimal
distortion and enhanced peripheral illumination. A member of Canon's
legendary L series, this full-frame 16-35mm delivers outstanding image
quality and a professional-grade durability. It also offers a fast and
constant f/2.8 maximum aperture for consistent performance and light
transmission throughout the zoom range.
With the incorporation of two large diameter GMO dual surface aspherical
elements and one ground aspherical element, the lens will minimize
distortions throughout the zoom range as well as maintain edge-to-edge
sharpness and illumination. Along with those elements, the lens utilizes
two Ultra-low Dispersion glass elements which minimize chromatic
aberrations. Also, it uses both a Subwavelength Coating and an Air
Sphere Coating to minimize flare and ghosting.
In terms of handling, the 16-35mm uses a ring-type USM focusing motor
combined with a high-speed CPU and optimized algorithms for lightning
fast and accurate autofocus. The lens has an internal focus design and
offers full-time manual focus override so users can make tweaks using
the physical focusing ring regardless of mode. Along with all of this,
the aperture diaphragm uses nine rounded blades to create smooth bokeh.