Most interviews with Canon employees are exercises in vague platitudes. Not this one (in Japanese). Product planning executive Kengo Iezuka indicates why they chose to pursue the much-praised poor man’s super telephoto lenses 600mm f/11 and the 800mm f/11. It boils down to the fact that they knew they could with two new facts: mirrorless AF working in lower light conditions; and a massive reduction in the cost of producing DO lens elements.

When the interviewer asked why not a 400mm f/8 version, Iezuka reacted with surprising candor. Yes, they’d like to make one, but it depends on the reception of the 600mm and 800mm versions. So far it seems these have been very positively received. “I think it will be an attractive lens,” said Iezuka.