However, what really surprised me was how well the AF tracked when shooting video. I also shot a number of High Speed video clips, and I was blown away by how well this camera/lens combo was able to acquire and track the racers, even with the quickly changing distances. 

 

For AF settings, I used the "Multi" setting in the X-T4's movie AF/MF menu. This lets the camera choose the subject. In "Area" mode, you have to choose where the camera focuses with the AF joystick. You can also adjust the Speed Tracking and Sensitivity inside the movie AF Custom Settings menu, but I just left them at their default values and got great results.

 

After the race, I edited the clips together and set them to one of my original songs It's pretty fun! You can watch the video on my YouTube channel. and you can check out the stills from the race on my Facebook page.

 

If you don't have the 100-400, rest assured that all of the latest Fuji model cameras have excellent AF tracking, and with a little practice, you can get awesome results shooting things that move.