What Is Back Button Focus And How To Use It?

Automatic settings on modern cameras are fantastic and can take away a lot of the mistakes that both novice and some expert photographers might make. However, if you aren’t fully aware of everything that your camera is capable of, are you really getting everything out of it that you can?

One common mistake made among newcomers to photography is the difference between back button focus and back focus. In this article, we’ll take a look at both, but mainly the back button focus and how to use it. Before long, you’ll know exactly how to best use this feature and you won’t have to worry about confusing it for something completely different ever again.

What is back focus?

Back focus is really very different from back button focusing, so to make sure you don’t get them mixed up again, let’s take a quick look at back focus.

Simply put, back focus is when the lens of your camera is focusing on something behind your subject. It can be a frustrating occurrence in photography if you don’t know exactly what’s happening. Your camera is automatically trying to focus on the wrong thing, and therefore your subject, or the intended target of your image, is out of focus.

It’s a common problem with autofocus in general and one that is easily avoidable. Just adjust the focus manually and you won’t have to worry about this annoying automated mishap any longer. You could also apply a decent focus chart to help you coordinate how your focus should be set, and for help with this, there are many online tools.

Okay, I got it – now what is back button focus?

Typically, on most cameras, this is how autofocus works: when you press the shutter button the camera does its best to focus on your intended subject. Back button focusing is a way of not allowing the shutter button to control the focus, which is alternatively controlled by a button on the back of the camera.

This gives you a little more control over focusing while still allowing the camera to make the adjustment for you. It’s not so much a time saver as it is a control issue and it can be handy in a couple of different scenarios.

Who came up with back button focus?

Way back in 1989, Canon developed a camera that was the first to use the back button focus feature (and that particular model would be the EOS 630 (35mm film SLR)). Since then it’s become pretty commonplace, used in all EOS digital SLR models, although it’s not always intuitive to turn on.

While some models have a dedicated back button focus, some use an ulterior button such as the AF-L, AE-L button. For example, certain Nikon cameras have this just like some Canon models. Some will allow for programming of the back button focus feature, so make sure you check out your manual for how to turn this on if desired, or if you have a dedicated button. This is why you may hear some photographers refer to back button focus as back-button AF.

When should you use back button focus?

You might think that not allowing your camera to adjust the focus for you at all is preferred, and some photographers work this way. However, it really can be beneficial in some cases, so let’s take a look at a couple of examples.

Example 1

Let’s pretend that you’ve been hired to shoot someone’s portrait. The subject is positioned so that they won’t be moving around, allowing you to take different shots of the subject from different perspectives.

You take a quick shot and then change your position, forcing you to refocus. A lot of DSLR cameras will make you tediously move the focus point using the selector. This can be a little annoying.

The back button focus is a possible, and easy, solution to this situation. If the distance between yourself and the subject, who don’t forget is standing still in this scenario, remains the same, then its only the composition that changes. If that’s the case, then the back button focus will let you adjust the focus quickly as many times as you need (in actuality, you’re really just telling the camera to make the automatic adjustment for you). Just make sure that you’re using a shallow depth-of-field.

Example 2

The back button focus can also be useful in our next scenario: let’s say that your subject is still immobile, but other elements creep into your proximity. Perhaps everyone has come to photograph a rare flower. Now imagine that other photographers are all clamouring for the same shot as you. All the photographers getting in each other’s way for the best shot, including yours. Someone has walked between your lens and the flower, and now your autofocus has focused on that person’s head instead of the subject.

Your back button focus can solve this problem by ensuring that it locks focus on your original subject. So that you stay focused on the flower instead of anything else.

Is back button focus for all photographers?

The question isn’t if back button focus is for all photographers but rather own to personal preference. You should spend some time getting to know your camera’s features and practising with the various focus options. Back button focus is a great tool to use on the fly, so be aware of its existence on your particular model should you plan to come into a scenario where you think it may be needed.

Using back button focus can make photography a little complicated for novice photographers, so test it out before you depend on it in a given situation. The screen options, should you have a camera model that requires some option swapping to turn on the back button focus, can be a little complex. Again, check your manual and get a real feel for your camera’s capabilities.