Use Back Button Focus to ensure you never miss a shot again. Read on to find out why and how to set it up

Back story…

Our muscle memory is set-up so we expect focusing to happen when we press the shutter button. But that’s a relatively modern development, which while it does mean the amateur is going to get more shots in focus (because they can’t forget to re-focus between shots) it’s far from ideal for a professional or enthusiast photographer.

Back to Basics - what is BBF?

With risk of simply re-stating the question, it’s a camera setup technique where the focussing is enabled by a button on the back of the camera, rather than the shutter-release button.

All DSLR and Mirrorless cameras support this technique, even smaller consumer DSLRs. Leica cameras work bit differently, so these are the only I’ve found that can’t be setup in exactly the same way, although they can be configured to get most the benefits. Besides, if you can afford a Leica camera, then you can afford someone to focus your camera for you!

back up a moment - how do you set it up?

Setting up BBF is very easy. To enable this mode, there are three steps.

Configure a button on the rear of the camera to trigger the auto-focussing. Most higher end cameras have an AF-ON button for this specific purpose, but if not, you can override the AEL or AF Lock buttons (you won’t need them). Sony cameras have an AF-On button which is, by default, configured to do the right thing. If it’s been re-assigned to something else go to (on A7iv) Settings->Setup->Operation Customize->Custom Key/Dial Set.->Rear 1-> and choose button ‘2’. Set this to AF On
Turn off the focussing system from the shutter-release button. This is done through your menu-system. On the Sony A7iV head to AF/MF settings->AF/MF and set option ‘AF W/ Shutter’ to off.
Set your camera into continuous auto-focus (AF-C on Nikon or Sony, Servo on Canon)

Now you’re ready for BBF. It will feel weird at first because the shutter-release button will NOT focus. To focus, you now press (or press and hold) the AF-On button to focus. When you want to take the shot, you simply press the shutter release button.

In my photography workshops where we use this technique, it’s sometimes reported that the camera is not focussing. This is normal initially; the camera IS focussing, but we just need to re-wire our muscle-memory. Give it a couple of days, and you’ll never go back to using a traditional setup.

Back of the net (I’m running out of ‘backs' here - can you tell?)

So what are the benefits? This is best answered by some scenarios of problems with the traditional setup. They are all solved by this single button and when and how you use it, no more camera focussing configuration is ever needed.

Shooting a landscape photo:

Imagine the scene with the traditional setup: You’ve got your camera ready, you’ve accurately focussed on the point that you want to ensure front to back sharpness across the whole shot. now with the shutter-release button half-pressed, you’re ready to shoot.

But wait! The composition is not correct and you’re waiting for the sunset to be perfect. So you need to get your camera moved, and wait 24 minutes for the right light. You can’t half-press your shutter release for that long and you let go accidentally, so you have to go right back to the start again. Sure you ‘could’ use the manual focus switch on your lens, but did you touch the focussing ring as you did it? You did, didn’t you? You need to check, back to the start. Even if you manage to take the shot, for the next shot you need to do the same thing again, back to the start each time.

If you’re on a tripod, this is infuriating!

With BBF, you press AF-On to get the focus you want, then let go. Now whatever you do with your camera, it will not change focus. You can get your composition correct, wait an hour, and then shoot shot after shot, all with the same focus.

You’ve effectively got yourself an option to lock focus without having to hold anything.

Shooting pre-emptively

You’re photographing a car/bike race or something with a LOT of motion. You’ve switched to AF-C mode, so that you can cope with the changing focal distance. As them come past you you need to half-press your shutter release button and track them to keep them in focus. You might get a good shot, but careful composition is going to be impossible.

With BBF, you simply focus your camera on where you know the competitors WILL be, get focus and then let go of the AF-On button. Get your composition as you want it and now you just sit and wait for the perfect moment. As they come past, burst mode and you have 100 shots all in focus.

A few pictures with movement or elements that would be almost impossible to capture without BBF.

Switching between AF-S and AF-C

You’re shooting an event, sometimes you want AF-C for when subjects are moving (especially if it’s towards you) and sometimes AF-S for a portrait. Swapping between these two modes in the menus slows you down.

With BBF, there’s nothing to do. If you want AF-C behaviour, you simply press and hold your back button while you shoot (the camera is set up in AF-C mode for this reason). If you want AF-S, type behaviour you simply let go of the back button and shoot without changing focus. You can decide on each shot how you want the focussing to behave, all with that one button. In a studio for example, you might even go for manual focus to ensure no changes to focus between shots. Fine, use BBF to focus that first shot, and then don’t touch it again. Voila, manual focus.

There are dozens of other scenarios, where BBF will make your life easier and each of us find different benefits, but most people DO benefit hugely if they give it a bit of time to sink in.

So if you’re using AF-S and AF-C at different times, or are using AF-Hold (with a button or half-press of shutter) or switching to manual focus to lock in the perfect focus distance, then this is going to be a game-changer. If you’re not doing either of those things, then you should be, and then you’ll benefit from BFF.

My ideal setup

I use Back-Button Focussing on the AF-On button and EyeAF on the AEL button and never need to change my focussing setup. It’s the perfect combination of using the camera’s intelligence to find the subjects eye, while giving me the option of taking full and flexible control of focussing in an instant.

If you rely heavily on focussing modes such as object tracking, or you tap your rear screen to focus, then you are probably the only category of people that will not see any benefit of BFF. But even in these cases, those modes do go wrong sometimes, and when it does you need to be able to control your camera and BBF lets you do that perfectly.

Nick Church Photography Education

This is one technique that I teach in my photography workshops. There are courses for beginners using a camera for the first time, all the way through to professionals looking to take their work to a new level. Courses run in-person at my Studio, or via Zoom. Zoom sessions can be a full workshop, delivered over multiple sessions, or a single one-off call to coach you on any issue with photography, film or editing. Full details here

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