Canon is planning to announce at least two new “big white” super telephoto prime lenses ahead of Photokina 2018. One of the big white lenses is now confirmed: it is the Canon EF 400mm f/2.8L IS III USM lens.
The second one from Canon is still unknown at the time of writing, but it will be a version III lens, probably EF 300mm f/2.8L IS III USM lens, EF 500mm f/4L IS III USM lens or EF 600mm f/4L IS III USM lens.
The main upgrades for these lenses will likely focus on weight reduction and updated coatings. And the optical formulas is expected to remain about the same.
Reminder: In June 2018 Canon officially announced the new EF 70-200mm f/2.8L IS III USM and EF 70-200mm f/4L IS II USM lenses.
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