Roger over at LensRentals.com has taken some time to test a variety of Canon 400mm lenses, including the new EF 200-400 f/4L IS 1.4x.
Roger’s initial take…
“I can’t say whether it’s worth the price or not, but I can certainly say it’s the sharpest zoom lens I’ve ever seen, with image quality rivaling the most expensive primes.”
He did note however, that the 200-400 is a bit shorter at the long end than the EF 400 f/2.8L IS II. They’ve come to the initial conclusion that it’s about 95% of the 400 2.8 primes focal length.
Canon EF 200-400 f/4L IS 1.4x $11,799