The Canon RF 200-500mm f/4L IS USM could be announced as soon as November and it is being reported that it will come with a built-in 1.4x teleconverter built-in. The Teleconverter will be useful and make the lens into an effective 280-700mm f/5.6.
Canon RF100-500mm F4.5-7.1 L IS USM:
B&H Photo / Amazon / Adorama
via Weibo