AF tracking learning curve

I’m gradually getting higher percentages of in focus shots in 12fps sequences. Here are some general observations I’ve made, which apply to the kind of subject matter you see here.

First, there appears to be a difference between focusing speed of the 16-50 f2-2.8 and the 50-150 f2.8. The same occurs with my Nikon 24-70 f2.8 and 70-200 f2.8. The shorter lens is more difficult to use for this kind of tracking, which makes sense, because that is not the way most of us use it. The longer zoom is, at least in my case, al most exclusively used to track motion. I mention this because so many people seem frustrated in their attempts to use the shorter lens for tracking.

I’ve mentioned that counter to what most of us would expect, the multi point AF screen is the one I find works much better for tracking action. It is much more difficult for me to be successful when using the single single point for tracking, but it is my choice for static subjects. I’ve also found it is quicker to focus in low light if you set the largest size focus point, but sometimes I’ll dial it way down (in size) to make sure the plane of focus is exactly where I want it. I think it’s pretty obvious how you use the single point AF, but there are some things you can do that I find help me get better success with tracking using the multi point AF screen.

The two most important things I find to be helpful really need to be done together. First, make sure you have the little green squares on the subject before you take any images, and equally important, get the cluster of lighted green squares on the part of the subject you want to track before you make any exposures. You can raise, lower, tilt, the camera, whatever it takes, but if those active AF areas, the green squares that indicate the plane of focus, are not on the face (in my examples), you’ll be lucky if you get any images with the plane of focus where you want it. I’ve posted a couple of sequential images (2582 and 2584 at 12fps) from a high percentage in-focus sequence. The added difficulty here is the log in the foreground - a natural magnet for the multi point AF system, and the fact the dog’s face is in varying positions on the focusing screen as he runs and jumps. It’s a test (I know from experience) that challenges a camera’s tracking AF. I have another sequence from this morning - 22 or 24 images, I forget which, where all the images are in focus. The dog was trotting not running, which makes things easier. This is not something I would count on, given the relative rarity I’ve been able to achieve this since I’ve had the camera. I’ve seen discussion about the focusing speed, with people sharing a range of experiences. One interesting observation I’ve made when looking at sequences in LR, is 12fps sequential images can be in, then out, then in focus, meaning the shift is very fast. I’ll post some photos from the 16-50 f2.8 taken in low light in another thread. The dog jumping the log, images 2583 and 2584 were taken at 12fps, 150mm at f2.8, 1250th, ISO800. I hope these ideas will be helpful to at least some of you.