The Canon EF 600mm f/4 DO BR lens rumored to be announced in late 2017
Canon already had a prototype of the EF 600mm f/4 DO BR lens on display at the PhotoPlus show last year. There has been also multiple patents filed for this lens. The officially announced is now rumored for late 2017 according to Canonrumors. Here are few more pictures of the lens prototype - this thing is massive:
Pictures credit: PhotographyBay