So, for the past several weeks, you’ve been practicing the focus-recompose approach (because changing out those focal points on the fly turns out to be a nightmare) which means you focus on your child, recompose your shot, attempt to take a shot and then have to do it all over again, because your child keeps moving and your camera keeps re-focusing on wherever that focus point is now and you’re out of focus already. Whew. It’s exhausting!
If you’re like us, you’re thinking, “there’s got to be a better way,” and there is! Today we’re going to introduce you to back-button focusing.
Before we dive into back-button focusing, let’s review what we learned in focal points and focusing basics.
You’ll recall that by looking into your viewfinder, you will see a number of dots on screen that we call auto focus points. Depending on the camera, some of those points will be stronger than others. For most DSLRs, the center auto focus point is the strongest. However, you can manually select any single focus point available to you and place that on whatever you want to be in focus on your subject (preferably your subject’s eyes).
If you are using the focus-recompose method, you’ll hold the shutter button down half-way, wait for the focus square to beep and flash red. Then, once your camera has locked focus, you can go ahead and just shoot the image, or re-compose the shot (while still holding the shutter release button half-way down which locks the focus point) and then press the shutter to get the shot you want.
For some photographers, this approach works just fine, but it can be exhausting and frustrating if you miss the shot because your subject moved out of your focal point–which brings us to back-button focusing.
Why Should You Use Back-Button Focusing
With back-button focusing you are separating the two functions of focusing and capturing an image. You press a button on the back of your camera to focus, and press the shutter button when you’re ready to take the picture. Once this designation is established in your camera’s menu of settings, the shutter button will no longer try to achieve focus, because it no longer has the ability to do so.
You Won’t Miss THE Shot
Most of the time, you’re going to be photographing your children. When they’re young, you’re often lucky to capture anything since they’re moving so quickly. However, as they get older, their movements may become a little more predictable. For example, your child is working with finger paints. You really want to capture the joy on their face and ask them to look up. If you were just using the focus-recompose method, you might miss the moment. But with back-button focus, you can have your focus set and be free to shoot at that exact moment in which your child looks up with a smile.
That said, you can still use back-button focusing with even your wiggliest subjects. Just set your camera’s focus to Al Servo AF to track their movement, keep your right thumb on the back button to keep your focus active and your index finger can be ready to shoot.
Fewer Action Focus Errors
If you enjoy taking action shots, back-button focusing allows you to stop focus whenever something might interfere with the moving subject you’re tracking. However, it doesn’t require you to stop shooting! Just pull your thumb off the back button (your camera will stop focusing) and you can keep shooting by pressing the shutter button. Once the distraction is out of your way, you can quickly start tracking your subject again by pressing the back button with your thumb again.
As a photographer, this gives you even more control over the images you’re capturing. Not that it’ll prevent people from saying things like “your camera takes really great picture,” but it’s a step in the right direction. The more you control your camera (versus allowing the camera to auto select), the stronger images you will produce!
How to Activate Back-Button Focusing
Back-button auto focusing is enabled by setting the appropriate “Custom Function” within your DSLR’s settings menu (assuming that you’re using Program, Aperture-Priority, Shutter-Priority or Manual Exposure Mode). Unfortunately, we can’t provide you with a one size fits all tutorial for making this adjustment to your camera since every camera is a little different. But, now that you know what back-button focusing is capable of, try doing a search for how to set back-button focusing with your camera (example: Canon Rebel T5i) on Google or YouTube.
Once you set it up, all you have to do from there is practice practice practice. While using this approach does take a little getting used to, we promise the results are completely worth any frustration you’ll experience with the learning curve.
With all of that said, you’re welcome!
Now you can focus on your subject using the most powerful focus point you have, re-compose your shot and shoot as many images as you need without having to re-focus. YAY! As long as your subject stays on the same focal plane, you’ll never have to re-focus your shot using back-button focusing. Now you can spend more time capturing moments as they happen without your camera constantly trying to achieve (or miss) focus!
Photo Credit: Ashley Sisk