Photography Life have finally got their
review up for the 400mm f4.5, one I've been waiting for as I'm curious as to how it performs by the numbers.
The interesting observation, going by these numbers, is that the 400mm f4.5 is the least sharp lens I own!
Not sure wether this shows the strength of the Z mount being so much bigger, or if it shows that telephoto lens design is harder than you think (or a combination of the two), but my f2.8 zoom lenses are all sharper than a (exotic?) telephoto prime! Imagine saying that back in the days of the F mount!