Why the back button focus technique is a photographer's BFF

Back button focus technique – how to use it and why it’s your BFF

Back button focus for moving subjects

I can’t remember when I became best friends with back button focus. Like all great things, it’s something that I just started using and never looked back.

What is back button focus?

The clue is in the name. The back button focus button is on the back of your camera close to your right thumb and can be assigned the focusing function instead of the shutter button.

This allows the shutter button to be used just for taking the shot only and cuts out the common problem of refocusing between shots.

Exactly which button and what it’s called varies between camera brands so I’ve listed these further down in the article.

Why you should use back button focus?

It’s really quite logical. If you are already focused when you push the shutter button to take the shot, the camera has less to do in that minuscule split second of time.

Of course, without back button focus, you would have been depressing the shutter button slightly to focus anyway ahead of actually fully depressing and taking the shot.

But what if your subject, or you, moved a bit in that brief interval? Your camera would have to refocus before taking the shot.

The back button is a little focus Scout - always prepared.Click To Tweet

Within 5 minutes of first using back button focusing, without even thinking about it, my thumb has not left the back button. Except for when I put my camera down that is. It just makes sense.

Back button focus for moving subjects

When photographing young children back button focusing is essential – they move so fast! All the time.

Further reading: Freezing motion with a fast shutter speed

What button is used for back button focus?

Different camera brands call the back button focus button different names. Even the button used varies between the camera models in each brand. What they all have in common is that the back button focus button is the most convenient button for your right thumb to reach on the back of the camera.

Here’s a list of the buttons top camera brands assign to back button focus:

  • Nikon – AF-ON  or  AE-L/AF-L
  • Canon – AF-ON  or  AE Lock
  • Sony – AF/MF AEL  or  AF-ON
  • Fuji – AF-L  or  AE-L
  • Olympus – AEL/AFL  or  Fn1

What else is involved with back button focus?

To get the most out of back button focus, your autofocus should be set to continuous servo mode for Nikon or AI Servo for Canon. As the name suggests, your camera will continuously focus all the time you hold the button down.

I even use continuous servo for close-up still life images. The subject might not be moving, but I move fractionally every time I breathe in and out. Also, I don’t have a particularly steady hand, which is really annoying for a photographer.

What about autofocus area?

Don’t use auto area autofocus

There is no point being in auto area autofocus, AF-A for Nikon or AI Focus AF for Canon, if you’re using back button focus. It’s far too general and the camera won’t know what you want to focus on.

That’s why if you use this autofocus area you’ll find every now and then that your subject is completely out of focus and some random object in your image is beautifully in focus. I’d go so far as to say, don’t even bother with auto area autofocus.

Further reading: One Shot vs AI Servo vs AI Focus – which AF mode is best?

How to use back button focus

I used single point autofocus in continuous servo with back button focussing and a high shutter speed to ensure a sharp photo of this very fast moving and delightfully goofy dog barrelling down the hill to his owner when called.

Use single point autofocus

Take control of the situation and choose single point autofocus (same terminology for both Nikon and Canon).

Position the focus point on your subject. If you’re photographing a person, and they’re close enough, position the focus point on their eye – the one nearest to you. Do this and your camera will be ready to take a perfectly focused image when the moment arrives.

Here’s a handy cheat sheet for Nikon and Canon autofocus area modes. Pop up your details and we’ll email it to you. As a bonus you’ll also receive our photography tips every Monday. You can unsubscribe at any time, no hard feelings.

 

Move the focus point

Also, get really, really good at changing your focus point really, really fast to keep up with your subject when using single point autofocus.

I don’t see how you would get a well focused image of a moving subject if you’re not using back button focus, along with continuous autofocus. For DSLRs you also need to use either:

  • single point autofocus
  • 9 point dynamic area autofocus
  • or 21 point dynamic area autofocus

Dynamic area is a Nikon term. Canon’s equivalent terminology is AF point expansion.

Mirrorless cameras also have the big advantage of eye autofocus.

Further reading on how to get the most out of your autofocus:

Nail your autofocus, get the shot

How to focus on fast moving subjects

To be a good photographer you need to develop your inner control freak.Click To Tweet

Have you used back button focus?

Have you made the switch to back button focus yet? If so, let us know in the comments what you photograph. Also, when you made the switch, how much of a difference did it make?

If you haven’t, you need a new BFF and BBF is the one!

Leave a comment

We love to hear that we’re being helpful, so if this tutorial has helped you to understand back button focus, share that too!

Will this photography tutorial help you to take sharp photos?

Share the learning… pin it, post it.

2.0K Shares

10 thoughts on “Back button focus technique – how to use it and why it’s your BFF”

  1. I enjoyed your articles and while reading about bbf I had not set my Auto focus to S. I have been very pleased with my camera operations using bbf and would highly encourage others to try it. There is so much to learn and I am greatful to people like you who reach out and share your knowledge. Thank you!

    1. Thanks so much for your comments, Debbie. Hearing that something I’ve written has helped somebody, even just a little bit, is the best feeling in the world! Just one thing – I’m sure it was just a typo, but just in case… Make sure when using back button focus that you have it set to continuous focus (c) rather than single focus (s).

  2. Adebayo Fashina

    Thanks for the tips I appreciate but I would suggest you show pictures of how to operate the back button and where it’s located in the camera thanks

    1. Hi Adebayo. Thanks for your comment.

      Different camera models have different buttons for back button focus, and not all have a dedicated BBF button. The more advanced Canon and Nikon cameras do and it is labelled AF-ON. On other cameras you can assign the AF-L AE-L button to be your BBF button. You’ll need to use your camera’s menu to do this. Again, this varies with different brands, but your manual will be able to guide you.

      As Canon and Nikon are the most popular brands, I’ll mention them. If you have a Canon, look in your menu for “Shutter/AE lock button”, then select “Metering start/Meter + AF start”. If you have a Nikon, use the custom setting menu, go to controls, select “Assign AE-L/AF-L button” and then “AF-on”.

      As to the location – it will be on the back of your camera, on the right, at the top – where you thumb can easily reach it.

      Hope this helps.

  3. I am just not getting something on this. I use an Olympus (but I suspect that doesn’t matter). If I am on Continuous-AF then a half press on the shutter starts focus and continues focusing until the full press. (If I want to separate exposure then I press AEL first.) How is that different from pressing a different button, except that with bbf you still have the whole shutter press to make rather than just the remaining half-press?

    1. Hi James

      Thank you for your question.

      Part depressing the shutter button and using continuous-AF certainly does work to maintain focus, but the disadvantage is that you must then refocus after taking the shot. With a still subject that is no problem, but with a moving subject, you could miss the shot while your camera refocuses.

      If you use back button focus and continuous-AF when photographing a moving subject, your camera continuously focuses on your subject, even while taking the shot. This is why back button focus is particularly useful with moving subjects.

      Separating the focus and shutter functions also avoids accidentally depressing the shutter button fully and taking a shot before you’re ready and then potentially missing out the moment.

      I hope this helps.

  4. Hi Jane love your comments on back button focus there is just one thing i”m still not clear when I hold down the AEL button on my Nikon do I hold down this button all the time and them take my finger off AEL or do I keep it on until I have finished? again I would like to say thanks for your great tips

    1. Hi Tom

      Thanks for your lovely comment! To answer you question, hold the button down the whole time you want to focus when your subject is moving. Only release the button when recomposing for a different shot or when you lower your camera. This way, you’re guaranteed to be ready to take a shot.

      If you’re photographing something that isn’t moving, hold down the button to get focus and then release it. If neither your camera nor your subject moves, you’ll be ready for the shot and just need to push the shutter button (as long as you’ve previously gone through the process, via the camera menu, of isolating the shutter button for taking the shot only without focusing).

      Hope that helps.

  5. Thanks for all the info and tips you provide…and the hard work behind them.
    All very simple, clear and easy to understand and apply.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top