It would be fair to say that we have all become so used to the half-press shutter to achieve autofocus that any change to this routine would seem a little strange. For those of us who remember, of course, there was once a time in photography when autofocus simply did not exist, or was at best a crude mechanism.
In this article, I will explain the benefits of an alternative to using the shutter to focus on your subject called Back Button Focus. I will outline the problems with the way we use the shutter button on cameras now and the distinct benefits of using Back Button Focus instead.
The Problem with the Half-Press
Automatic focusing technology has improved to the stage where we rarely even question its accuracy, and top of the line DSLR and Mirrorless cameras from big players in the market like Nikon, Canon and Sony all feature amazing autofocus technology that is fast, accurate, and makes life a lot easier. But none of this means that the art of manually focusing doesn’t have a place in photography. In fact, many street photographers use manual focusing religiously, and when taking a photo of a landscape from a tripod, the usual routine is to autofocus and then switch the lens to manual focus so that multiple shots can be made without having to half-press the shutter each time and lose the initial point of focus.
The last point is important. We’re all so used to the shutter buttons on our camera locking focus on a half-press that we often don’t think about how it might be slowing us down. Here’s one common problem: if you’ve already focused on your subject but want to take multiple photos, do you really want to refocus each and every time you half-press the shutter button? Wouldn’t it make much more sense of the shutter button only activated the shutter?
The Benefits of Back Button Focus
If you could alter a setting on your DSLR that gave you the option to use autofocus, but also meant that you didn’t have to refocus each and every time you pressed the shutter button, it would make many photographic situations more convenient. On most DSLR cameras, you can do this right now. The feature is called Back Button Focus.
By setting one of the function buttons on the back of the camera – usually the Exposure Lock (AEL), or similar free button – to be the focusing button, you free up the shutter to be the button that actually makes the shot. By separating the shutter from focusing, you take control over when you want to focus. But how can it improve your photography and why is it better than half-pressing the shutter button to achieve focus? When you consider the following benefits, you might not ever want to go back to the half-press again!
Below are a few examples of Back Button Focus locations on different camera models.
Predictable Focus Every Time
Back Button Focus is especially good for situations where you want to take multiple photos of the same subject. For example, if you’re involved in a portrait session, do you really want to have to refocus every single time you half-press the shutter button? You can focus once on the subject’s eyes with the back button, and then take multiple shots with the shutter button. When your subject changes position or you want to focus on something else, you can simply press the back button to refocus. Even though it might take a little getting used to, you may never go back to using the half-press again!
Speed and Efficiency
Using the re-programmed back function button to focus when YOU want to and not whenever you depress the shutter button is simply more efficient. You will find yourself re-focusing less and concentrating far more on the subject and composition. Even though most modern cameras are very quick at achieving accurate focus, you don’t always want to have to wait for the camera to refocus on a subject. Back Button Focus means that you can lock focus once and then use the shutter for what it was really designed to do: activate the shutter in the camera and take a photo!
Before shooting a vertical panorama of Horseshoe Bend, I used Back Button Focus to lock the focus and then I shot series of the shots without worrying about focusing.
Real Life Examples
I have already discussed the benefits of using Back Button Focus for portraiture, but it also imparts great benefits to many other types of photographers.
For many landscape photographers who regularly use a tripod in their work, separating the shutter from focusing is very convenient. If a photographer already has their camera set up on a tripod and focused on the landscape in front of them, they don’t need to refocus each and every time they take a photo. In fact, many landscape photographers focus once and then switch the lens to manual mode so that the camera doesn’t refocus when they press the shutter button. This situation can easily be avoided when Back Button Focus is set up.
For landscape photographers who use filters regularly, using a back button to focus makes their session far more convenient and just makes good sense. It would be inconvenient for them to have to refocus through a filter, especially since many filters are so dark that focusing would be impossible for the camera to achieve.
I use the Back Button Focus functionality to lock the focus one third into the scene and after the focus is locked, I recompose to get the composition I want.
Wildlife photographers often find themselves waiting for animals to make a move or do something interesting before they take the photo. Leaving focusing to the shutter button in this situation means that every time you want to take a photo, you need to wait a little before focus is achieved once more on the subject. In this moment, that interesting pose or movement might be over, or the animal might even have moved out of frame! Back Button Focus solves this problem by freeing up the shutter button to make the shot without having the delay of refocusing.
The Back Button Focus technique becomes even more powerful in combination with Continuous Autofocus mode. It allows a photographer to lock focus on a subject once and then concentrating on shooting while the camera keeps tracking the moving object adjusting the focus accordingly. This combination is widely used by wildlife photographers when shooting flying birds of running animals.
In much the same way that wildlife photographers often find themselves waiting for just the right moment to take the shot, street photographers also spend a lot of time looking for the right moment. By leaving focusing to the half-pressed shutter, a street photographer will have to endure many lost moments as they wait for their camera to refocus every time they want to capture a moment on the street. Setting up the camera to Back Button Focus means that street photographers can capture moments as they happen without waiting for the camera to hunt for focus.
How to setup Back Button Focus
The process of setting up the Back Button Focus is different for various camera brands and models. Sometimes it is a single step process where you simply assign a dedicated button to AutoFocus. On other models, it a 2 or even 3 step process where you disable autofocus on shutter button first and in the second step, you assign AutoFocus functionality to one of the programmable buttons.
I am going to show you how to setup Back Button Focus on Sony a6000 and a6300. It is a 3 step process.
Setting up Back Button Focus on Sony a6000 and a63000
Disable Pre AutoFocus by setting Pre-AF value to OFF.
Disable AutoFocus on Shutter Button by setting AF w/ shutter value to OFF
Go to Custom Settings
Select AEL Button menu item.
Set its value to AF On
A Smarter Way to Focus
Once you set up your camera for Back Button Focusing, you may not ever want to go back to half-pressing the shutter! The speed, efficiency and convenience of Back Button Focus means that less moments are wasted waiting for the camera to refocus, and more crucial moments are captured.