The EF 600mm f/4L IS III delivers ultra-high sharpness and very low levels of distortion. Both Super UD and fluorite elements are used in the optical design to help reduce colour fringing and chromatic aberrations for high clarity and colour accuracy. Super Spectra and Air Sphere Coatings have been applied to individual elements to suppress flare and ghosting for increased contrast and colour neutrality when working in backlit conditions. The use of aspherical lens elements in the design helps to limit spherical aberrations and distortion for greater sharpness and accurate rendering.
An advanced optical formula not only boosts image quality but also makes the EF 600mm f/4L IS III more portable, making it easier to use on location. As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions and also features a fluorine coating on the front and rear elements to guard against water spots, smudges, or oil residue.
Sharp focus is achieved quickly and quietly, using ring-type USM autofocus. Dynamic subjects are tracked accurately as they move about the frame. With a fast f/4 aperture, the focus is quick and accurate even in low-light conditions. Extremely quiet autofocus operation makes the Canon EF 600mm III the perfect discreet companion in the bush when capturing wildlife.
With its radical lightweight design and five-stop Image Stabiliser, the EF 600mm f/4L IS III can be used without support, even with such powerful telephoto magnifications. Three stabilisation modes suit various shooting applications and include standard single-shot mode, a panning-optimised mode, and a mode that only activates the Image Stabiliser during the exposure.
Fingertip controls allow AF to be started, stopped or momentarily locked. Two pre-programmed focusing positions can be recalled instantly with the touch of a button. A customisable electronic focusing ring further contributes to precise manual focus control, by affording three focusing sensitivity levels for different applications.