AF-On And Back Button Autofocus

Posted on by Steve

Try a better way to focus your DSLR! Using back button autofocus is a faster, easier, smarter way to get great AF results from your DSLR. This video will show you how AF modes work – and why decoupling autofocus from your shutter release can take your photography to a whole new level.

This method works both for camera with a dedicated AF-ON button or by reassigning a button on the back of your camera for autofocus.



Follow Up Notes and FAQ

This turned out to be a really popular topic and I’ve had quite a few questions come in regarding this technique. So, I’ve put together some notes and a few commonly asked questions that should make the transition from shutter release AF to back button AF much easier.


When I try this technique on my Nikon, I focus and recompose, but my camera won’t fire. The only way I can get the camera to take a picture is if the AF point is right over the spot that I focused on.

This behavior occurs when the camera is set to “Focus Priority” for AF-C under the custom functions menu. By default, most cameras will use what’s called “Release Priority” when they are switched to AF-C mode, so most users will not run into this issue.

However, sometimes a camera is set to “Focus Priority”, meaning the camera will ONLY fire if it has a 100% focus lock under the current AF point. This behavior is fine when you’re locking in focus with the shutter release or you happen to have the AF point right smack dab on the area where you want to focus. However, with Back Button AF it causes an issue since you can no longer focus, recompose, and shoot (the AF point may no longer be over an area that’s in sharp focus).

So, make sure your AF-C focus Priority is set to “Release” under your custom menu. Usually it’s the first option for most Nikon cameras.


With shutter button AF, my VR was activated when I pressed partway down on the shutter release to focus. When I use the back button, VR no longer activates when I focus. How do I handle this?

The answer to this is going to depend on your camera. If you have a newer Nikon body (like a D800 / D4 etc), using the back AF-On button will actually activate VR. For older cameras, it’s only activated with a half press of the shutter release.

However, don’t let that stop you!

I used this method a long time before it was linked with the shutter AF-On button on the back of the camera. In fact, I prefer VR to be available with a half press (it still is with newer cameras, it’s just been added to the AF-On button).

The reason I prefer it with a half press of the shutter release is that I can keep VR active before the action starts. This is critical since VR needs a few seconds to stabilize before you start shooting. If you simply focus and shoot at the same instant – before VF has had a chance to stabilize – you’ve lost all the benefit of using it. So, use your back button to AF, and hold halfway down on the shutter release until and wait for that perfect moment. Then, just a little extra presser from your finger snaps the shot.


What about using dynamic AF? Like d9, d21, or 3d tracking?

No worries – it works exactly the same as if you were using your shutter release for AF. The next question is why / how to use those dynamic AF tracking modes, but that’ll be another video. (hint – most people should probably start with 21pt)


My camera used to beep for focus confirmation, now it’s not doing it – what happened?

Unfortunately, this is one downside of this method, you’ll no longer get that focus confirmation beep. However, I’ve learned to keep an eye on the AF confirmation dot in the viewfinder and have never really missed the beep. Besides, for the most part you can see if the subject is in focus or not right in the viewfinder. Old school style :)


Do you always focus with just the center AF point and recompose?

Nope, I did it that way for the video to keep things nice and simple, but most of the time my recommendation is to select the AF point that the closest to the spot you’d like to focus on. Sometimes you get lucky and you’re able to put the AF point right over the area you want to focus on, other times you’ll need to recompose, but at least it’s a minimal amount. Either way, this method has worked great for me.


Are there any limitations when using flash units?

Under normal circumstances, no, this works just like shutter release AF. However, this is one exception to the rule and that’s if you use the AF Assist Illumination feature – this method doesn’t support it (at least with Nikon).


Why do all these questions seem to involve Nikon cameras? What about Canon?

Unfortunately, I don’t own any Canon cameras at this time, so I can only speak to what I know about the Nikons and encourage Canon users to apply the concepts to their cameras. I do plan on getting a Canon body down the road for instructional purposes.

This tip is filed under:

30 Responses to AF-On And Back Button Autofocus

  1. Maria Sacadura says:

    Thanks for your video but as I nolonger have Canon ou Nikon Cameras I would like your help to use the back button on my Fuji X-E1. Should I use the Continuous foccus? I’m afraid of doing something wrong and be unnable to correct afterwards.Thanks in advance for your help.

    • Steve says:

      Hi Maria –

      Sorry, I’m not familiar with the fuji, so I can’t get too specific. However, I can tell you for sure that any camera will need to be set to continuous in order for this to work. Hope this helps :)


  2. Maurice Prokaziuk says:

    I am using the AF-ON button for focusing on my nikon D7100 and I love it. My only issue is when I use my battery pack the AF-ON doesn’t work on my battery pack, the focusing reverts back to the shutter button. Is there something I am missing in the setup?

    • Steve says:

      Hi Maurice –

      Hmm – not sure on that one – I don’t have a D7100. I wonder (and am guessing) maybe there’s a separate menu setting for the grip – in fact, I seem to remember something like that when I had my D7000 and a grip. Wish I still had it, I could figure this out, but take a look at the custom settings menu a little closer, I’m guessing it’s there.


      • Sam Feinstein says:

        When you attach a battery grip, the option to assign this function will appear in your menu system under “Controls” on the Custom Settings menu. Just assign “AF On” to the button on your grip. This applies to all Nikon cameras that accept a grip, as far as I know. Look for the model of your battery grip in the menu (such as “Assign MB-D11 AE-L/AF-L”) and that’s where you make the change.

  3. Denny Larrisey says:

    I have a nikon d7000 an would like to know if i use the back button focus method, if I am following a moving object,do I keep the af button pressed when I take the shot? or release af button then take shot? many thanks.

  4. Denny Larrisey says:

    Hi Steve, I have a Nikon d7000 and I have assigned the AE/L AF/L button so I can use it as a back button focus.When I focus then re-compose,the camera will not fire.I have set the focus priority to RELEASE but it still wont fire.Help.

  5. Denny Larrisey says:

    Update, I forgot to set the camera to af c on the camera itself.I have done this and all working fine now, many thanks Steve.

  6. Pingback: You’re not a real photographer if you rely on autofocus | PirateSnap

  7. Bill Sotak says:

    My Nikon D5100 and I must be missing something here. I’ve set the AE-L/AF-L button to AF-ON, the Focus Mode to AF-C, and the shutter to Release – as posted. Wnen I press the now AF-ON button, my focus point lights up RED as usual. Then, I release the buttonto supposedly lock that focus on the specific subject. However, when I recompose and press the shutter, the focus point lights red on a different spot. When I checked my focus point on test photos into View NX2, the focus point is NOT what I focused on with the AF-ON button. There MUST be something else I have to do.
    Need some help on this one as I like the idea of B Button Focus. Thanks!

    • Steve says:

      Hi Bill –

      I’m not overly familiar with the 5100 (my wife has a 5000), but I’ll take a guess. The only thing I can think of is if the 5100 is on one of the full auto or scene modes – I think this only works properly when it’s in Program, Aperture Priority, etc.

      • Bill Sotak says:

        More about my issue with BBF.

        For some reason, I cannot recompose after pressing BBF Button-as red focus light still comes on when I press shutter 1/2 way down after recomposing. It seems I need to find a way to cancel shutter focusing so BBF will work the way I want.

        I believe I’ll have to follow the following steps as opposed to focusing, holding BBF and recomposing.

        Step 1: Find best composition.
        Step 2: Move one of the 11 focus points appropriately.
        Step 3: Press BBF Button & release to lock focus.
        Step 4: Press shutter all the way.

        Bill Sotak

      • Bill Sotak says:

        Steve-per Nikon Support “Thank you for contacting Nikon. When using the AE/AF button on your D5100 the exposure settings will lock (aperture, shutter speed, and ISO). However, this camera will not allow you to lock the focus point by pressing the AE/AF lock button.”

        I am truly disappointed as I thought this was a very cool focusing method. Oh well. By the way-You probably should change your video as the heading references D-5100 even though you say D-5000.

  8. Bill Sotak says:

    Steve-I do have it in aperture priority.

  9. al gould says:

    Can I get a written copy of these instructions?

  10. Pingback: A Better Way To Focus Your DSLR | Worldstart's Tech Tips And Computer Help

  11. sephen hughes says:

    hi very new to this had a stroke on my left side but just love photography
    this may sound silly but does the af -on button act as a shutter realease
    as well or does it just help focus

  12. irwin lakin says:

    steve, i have the canon t4i and will set it up for BBF. I like to shoot images of hummingbirds at my feeder. Is bbf a good option to take these bird images as they move pretty fast over the flight of a seagull etc.Any special instructions here for taking them using BBF? Thanks!!

    • Steve says:

      Hi Irwin –

      I use it exclusively, no matter how fast my subject. Once you get used to it, you’ll probably find it’s actually faster to use the front button AF – at least that’s been my experience. A few weeks of practice and you’ll never look back.

  13. Wilson says:

    Hi Steve, first of all great article, thanks for the great tips. I do want to ask about metering while using AF-ON button for auto focus. When using spot or center-weighted and using AF Continuous to track the moving subject. It appears that the metering uses the first focus point for metering and does not move with the focus point when the subject moves. So in the case of high contrast subject and background, the metering might be off while the subject was successfully tracked by AF. How do you get around this issue so that the AF and AE points are in sync (i.e. metering on the correct subject along with auto focus)? Thanks.

    • Steve says:

      Hi Wilson –

      To be honest, I usually use matrix / evaluative metering, but the moment I see an issue, I’m pretty quick to just shoot manual and avoid the whole problem. Years ago I’d mess with spot and centerweighted (OK, years ago we ONLY had centerweighted), but I just don’t use it that much for the exact reasons you cite. Just easier to shoot manual, you just need to keep an eye on the light and change your settings as it changes.

  14. cj says:

    Love using this method of composing, but recently ran into a problem. My camera in AF-C mode, will not allow me to select a different focus point. Up until a few days ago it was functioning normally. All other functions of the camera are fine. Curious is this could be a firmware issue, or possibly something more. Any tips or info would be appreciated.

  15. Prabir Birr Sen says:

    Focusing on the bear’s eye and releasing the AF-ON button .. that’s fine. But what about locking the exposure?

    • Steve says:

      Really depends. Personally, I do one of two things. If the exposure isn’t changing as I shoot, I’ll leave it in Aperture Priority and dial in exposure comp as needed. If the meter is jumping around due to tricky exposure conditions though, I’ll just switch to manual exposure. With wildlife, you’re usually wide open or close to it, so really the only thing you’re adjusting is the shutter speed, so no biggie.

  16. Bruno says:

    Steve, I have been using your AF-ON tip for months now but when I rotate my camera in portrait mode to use my MB-D12 battery grip on my Nikon D800, my focus point keeps jumping around during exposure and as such I can not place it where I need to using the AF-C mode. My exposure mode is always MATRIX and my shooting mode is MANUAL so any idea what could be causing this and how I can resolve it?

    • Steve says:

      Hmm – that’s bizarre. AF-On shouldn’t make any difference when it comes to AF points. The only thing I can think of is maybe your AF points are set to 3D or something. Try it with single point AF and see if it still does it. I use this method on my D8XX bodies all the time, sometimes with the grip, and never have run across this. Very odd.

  17. Joe Gattuso says:

    FYI ..

    Nikon got back to me in regard to the issue described above .. specifically the need to turn off image review in the d5100 Playback Menu to insure (1) the prior image is not Locked/Protected and (2) the next shot if shot within the screen review time out period will not end up out of focus (AF-ON will not fail). They confirmed this is the way the d5100 is supposed to operate and suggest to avoid this problem to turn off image review in the Playback Menu .. Nikon was pretty quick .. 24hr and they were back to me .. hope this is helpful, note I suspect other Nikon’s without dedicated AF-ON buttons maybe the same in how they operate ? others I am sure can confirm this.

Leave a Reply

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

BackCountry Gallery