Lensrentals.com had some fun and tested various lenses at 400mm, some are zooms and others are primes. As you might expect the 400mm f/2.8 lenses came out on top, in price and performance.
I don’t think we really did too much here today except to have some fun and confirm, in numbers, what most people already know. The 400mm f/2.8 lenses, if you can afford one and don’t mind carrying it, are amazing. Canon’s new 400mm f/4 DO IS II is also superb, at least as good as the 300mm f/2.8 IS II with a teleconverter.
Canon’s 100-400 IS II is, from an MTF standpoint, the best zoom at 400mm, but the Nikon 200-500 and both the Sigma and Tamron 150-600s are also really good, far less expensive, and have greater range. The Nikon 80-400 VR II is not quite as good at 400 as the competition. Read the full article at Lensrentals.com
This is a great era in lens design, as it appears to be really hard to make the wrong decision.