Canon Patent: 500mm f/4 & f/5.6, 600mm f/4, 800mm f/5.6
Egami (translated) spotted a patent filed by Canon regarding 500mm f/4, 500mm f/5.6, 600mm f/4 and 800mm f/5.6 lenses. Patent Publication No. 2013-92575 Publication date 2013.5.16 Filing date 2011.10.24 Example…