The upcoming EF 16-35mm f/2.8L III lens is already in testing by select photographers, this lens will replace current EF 16-35mm f/2.8L II lens. According to CanonRumors, this lens will be officially announced some time in 2016.
This lens is a wide-angle zoom lens, designed for event, landscape photographers, previous rumors said the focus range could be slightly changed, like EF 15-35mm f/2.8L. Announcement could be along with EOS 5D Mark IV in March, 2016.
via: CR
Read More: Canon Rumors