Featuring L-series build quality, the EF 70-200mm f/4L USM is robust yet beautifully designed. As for optical quality, it has that covered too. You will notice excellent colour and bokeh in your images, and that each image is very sharp, even wide open. Meanwhile, vignetting, distortion and chromatic aberration are all very well controlled. The constant f/4 maximum aperture allows you to maintain a consistent exposure throughout the zoom range and also contributes to the sleeker form factor when compared to other 70-200mm lenses. In regard to its optical performance, this lens employs one fluorite element and two ultra-low dispersion elements, which work in concert to suppress chromatic aberrations and color fringing for notable clarity and color accuracy.
A Super Spectra coating has also been applied to control flare and ghosting for improved contrast when working in harsh lighting. Complementing the optical attributes, this lens also features a ring-type USM and an internal focusing mechanism for quick, quiet, and accurate autofocus performance, as well as full-time manual focus override.