I have been using back button autofocus for years now…it was tough to switch over, but once I did couldn’t imagine anything else. The biggest reason was I often needed to focus on a spot, recompose, and shoot. DSLRs don’t cover 100 percent of the viewfinder with autofocus points, so you just focus on the spot, recompose, and hit the shutter…pressing the shutter wouldn’t activate autofocus. But with mirrorless you can autofocus anywhere. Another big change with the Z9 is the camera just finds the eye/subject every time. I don’t need to be chasing the subject around in the viewfinder toggling the autofocus points.
Some wildlife photographers I know are now using shutter button autofocus, just like the ‘old days’. So I set up my Z9 for shutter button autofocus, and turned off back button focus. After about a two weeks of shooting this way, here is what I found.
First, photographing wildlife this way makes a lot of sense. The Z9 is so good at tracking the focus anywhere in the frame there is no reason to focus, recompose, and shoot. My thumb is now free to move my focus point around if I need to put it on my subject for initial acquisition. And while using heavy mittens all I have to do is find one button, the shutter, and the camera will do the rest. Even if an object comes in-between me and my subject for a brief moment, the camera is so fast at autofocus it just goes right back to the subject. This was another reason I liked back button focus, but the Z9 quickly refocuses.
With Z9 3D tracking using shutter button autofocus allows you to use your thumb to move the 3D focus point around quickly (using the large toggle) since your thumb is no longer hitting the back button focus button. On the other hand, all you have to do is put the focus point on the subject by pointing the camera at it (not moving the viewfinder focus point), press the back button down and the Z9 will stick to your subject where ever it goes in the frame. Lots of ways to autofocus…
So I am ditching back button focus? Nope. I think I may switch back and forth, but I still like back button for some situations. With landscape photography I like to focus on a point, and then stop autofocusing every time I hit the shutter….no need to do this. Moving subjects may confuse the autofocus point as to exactly where I want…and I still find situations where something might come between my lens and subject, and I just don’t need autofocus going back and forth every time.
I do think using shutter button autofocus makes a lot of sense now (with the Z9)…and I will be using it more in the future. Who knows, I may go completely back to this mode…I like having my thumb free to move the focus point in 3D tracking mode. Every photographer will find what works for them. The good news is the Z9 is so good at autofocus I don’t think it really will matter how you autofocus, the camera is going to nail autofocus. Try out shutter autofocus when you get your Z9, and see what you think. Always good to stay fresh and try out new things as technology changes!