Our camera can become an extension of our arm and hand, and changing the muscle memory we use to control it can be pretty daunting. However, spending time trying new ways of working can also be rewarding, especially when it makes life easier in the long run.
This video, brought to you by Sam Docker, discusses the fundamentals of why we might use back-button focus and gives a complete walk-through and setup demo. Sam is a very well-respected wedding photographer based in the UK. A few years ago, he turned part of his attention to educating photographers and has gained a following in the industry. His YouTube channel is fairly new, but is already bursting with content. His personality is cheeky but likeable, which reminds me of the great content from Taylor Jackson or Eric Floberg. I recommend taking a look.
Anyway, back-button focusing. This technique, in short, separates the autofocus system from the shutter release button. We then assign it to one of the buttons on the back of the camera under our thumb. At first, this feels simply wrong, but once we wrap our heads around what is going on and, more importantly, why, it all starts to make sense.
Ultimately, our reason for using back-button focus is control. Sam also goes on to talk about speed. We can focus and then recompose using this method. I love that my metering system is still attached to the shutter button, and I enjoy using spot metering with the half-press to lock my exposure while using the back button to focus my shot and keep it there.
Not everybody will gel with this technique, but every photographer will benefit from understanding the advantages.
I got serious about photography about 10 years ago. I had never heard of BB focus until I ran across a video from Tony&Chelsea and I haven't gone back to the default way of focusing. And now, with many of the newer cameras having the ability to go from single point to eye tracking by moving my thumb (R5), it seems to me the be the best way to use a camera.
I've never found any advantage to back button focus. More often, I found it to be a needless annoyance and delay, yet another way to miss the moment. It just means that, on average, every shot requires twice as much work: two finger presses instead of one. And mirrorless cameras with subject tracking and eye autofocus make it even less useful than before.
Once you go back, you never go back.
With today's camera's, BBF is slower and pretty archaic to me.
Slower than what?
Slower than single button click. Needing a thumb and a finger to take a shot is slower than just needing one finger. It becomes even slower if you need to move the focus point because now, you'll have to use your thumb to move the focus point, then, thumb back to the AF-On button, then, fire with your finger. Whereas with single button, even if are needing to move the focus point often, you can just keep your thumb on the joystick and finger fire.
Slightly more complicated movement, perhaps, but it’s not slower if you can move two fingers at once. The benefits for me of BBF is to decouple autofocus from autoexposure, and prevent refocusing when I click the shutter. I’d never move the focus point if I’m shooting handheld, I just leave it on center point AF, quickly center on what want in focus, and then compose my image as desired (which seems faster and less complicated than using the joystick to move the focus point around). So like the article says, there are advantages that may not benefit everyone, but I think there’s little question BBF allows for greater control.
--- "it’s not slower if you can move two fingers at once"
However, you're not moving two fingers at once initially. You're always going to have to AF-On first with your thumb, then, fire with your finger. I seriously doubt you're pressing the two buttons at the same time when you first set to acquire focus.
We like what we like. My son has been shooting weddings/events for quite some time and doesn't like BBF. I swear by it, but one small hiccup since I got my R5. The spacing of the buttons on the grip are different than on the camera body, so when I shoot in portrait grip, I have to think about when I move my thumb. It's automatic on the camera body.
I tried BBF a bunch of times, and always disliked it. I always went back to shutter button focus.