Rob Galbraith DPI: New 500mm f/4, 600mm f/4 in development, says Canon
The new lenses target improved dust-proof and moisture-proof performance in the face of harsh shooting conditions to satisfy the demands of sports, news and nature photographers, as well as high-contrast, high-resolution imaging from the maximum aperture setting.
Link: Rob Galbraith DPI: New 500mm f/4, 600mm f/4 in development, says Canon
Seeing that the new Canon 400 2.8 is 11,000 dollars, I wonder how much Canon will charge for these lenses