Doug Jensen
Carbonite Member
The discussion on another thread about the FX6's ability to track auto-focus on "objects" (rather than human faces with FACE/EYE detect) prompted me to pull together a bunch of footage I shot during July and August where I used PUSH-AUTO focus to track motion with several different lenses. I've found that the key to success is to focus as fast as you can manually on whatever subject you want to track -- then get your fingers off the focus ring and press one of the PUSH-AUTO buttons to tell the camera THAT is the object you want it to track. All of the lenses that I use (especially the 200-600) have a special button(s) on them near the focus ring that can be programmed for PUSH-AUTO. And sliding my fingers over to the button on the lens is much more convenient vs. the one on the front of the camera body.
As you can see, AF works great 99% of the time depending on how large the object is in the frame. If you jump to the very end of the video there is a three minute slow-mo shot of jogger coming towards the camera, and if you look close enough in the first 60-90 seconds you can see the focus slip for a second or two several times. If the shot was in real-time you might not even notice, but in 120 fps slow-mo you can see it. Once the runner is about half the distance to the camera from where he started the focusing is pretty solid. On the other hand, there is a three minute shot of a motorboat that comes just before the jogger, and I can't see the focus ever slip once on that shot. Same thing with the dragon boat paddlers. It never slips.
Another thing to notice is that there are several shots where a wall, pole, fence, other people, etc. obscure the main subject briefly but the focus holds on the subject rather than hunting for something else. All in all, pretty solid stuff. It was fun to shoot and the stock footage will more than pay for it all! I love this business.
As you can see, AF works great 99% of the time depending on how large the object is in the frame. If you jump to the very end of the video there is a three minute slow-mo shot of jogger coming towards the camera, and if you look close enough in the first 60-90 seconds you can see the focus slip for a second or two several times. If the shot was in real-time you might not even notice, but in 120 fps slow-mo you can see it. Once the runner is about half the distance to the camera from where he started the focusing is pretty solid. On the other hand, there is a three minute shot of a motorboat that comes just before the jogger, and I can't see the focus ever slip once on that shot. Same thing with the dragon boat paddlers. It never slips.
Another thing to notice is that there are several shots where a wall, pole, fence, other people, etc. obscure the main subject briefly but the focus holds on the subject rather than hunting for something else. All in all, pretty solid stuff. It was fun to shoot and the stock footage will more than pay for it all! I love this business.