Why the Sony 400mm f2.8 is worth $12,000

Sony 400mm f/2.8 GM Review (buy it at http://sdp.io/s400gm). With a Sony a9 (http://sdp.io/a9), is this is the ultimate sports photography combo? We test it out and compare it to the Canon 1DX Mk II with the Canon 400mm f/2.8 L IS II USM and the Nikon D5 with the Nikon 400mm f/2.8E FL ED VR .

Download samples at http://northrup.photo/downloads/s400samples.zip

Summary: The new lens with the Sony a9 did great. Focusing was as accurate as Canon and Nikon, but faster, and we got higher frame rates than we could with Canon and Nikon.