A revolutionary shift is on the horizon for Canon’s flagship super-telephoto prime lens lineup, affectionately known as the "White Lenses." According to the prominent camera rumor site Canon Rumors, the next-generation successors to Canon’s iconic sports and wildlife lenses—the RF 400mm f/2.8L IS USM and RF 600mm f/4L IS USM—are expected to be announced as early as the end of the fourth quarter ..