Mastering the AF-ON Technique with Nikon DSLRs

http://www.youtube.com/watch?v=WyPv1bLkwqA

On the rear panel of Nikon’s high-end DSLR bodies, including the D300, D700 and D3 series cameras, you’ll find a little button marked “AF-On.”  It seems kind of redundant to use this button for focusing when a half-press of the shutter release does the same thing.  Actually, I’ve found that setting the AF-On button to be the only way to activate AF is the best way to operate my Nikon’s AF system, but it requires a few set up steps and a little practice.

Why should you use the AF-On Only Technique with your Nikon DSLR?

The idea behind setting the AF-On button to be the only way to activate your Nikon’s autofocus system is simple.  Doing so allows you to set the camera to continuous-servo AF (AF-C) mode permanently, while still being able to get the benefit of focus-lock like you do in single-servo (AF-S) mode.  This means that at any time, you can switch between a focus/recompose/shoot style of photography (portraits and landscapes) and continuous subject tracking (sports & wildlife) without having to change camera switches or menu settings.

Also, with this technique, you decouple VR activation (half-press of shutter release) from AF activation.  That means you can be tracking a subject with AF and only engage VR when you want to.  This technique can save battery life in your camera!

How to set up y0ur Nikon DSLR to use AF-On as the focusing mechanism

The AF-On button is located on the back of most professional-level Nikon DSLRs
  1. Verify that your camera has an AF-On button.  If not, you’ll need to set up the AE/AF-lock button in the custom menus to use it as the AF-On button.  In the Nikon D90, this is custom setting f4.
  2. Set the camera’s AF servo mode to Continuous (AF-C).  This is done through the switch next to your lens mount, or via a custom menu setting. D90 users: hold down the AF button on the top of your camera, and turn the Main Command Dial until AF-C is displayed in the top LCD panel.
  3. In the camera menus, go to submenu “a” (Autofocus)
  4. Set custom setting a1 (Continuous Release Mode) to Release Priority (in the D90, this is already set for you when you choose continuous servo AF mode)
  5. Find the custom setting for AF Activation (a5 on the D3s) and set it to AF-On Only. This step is not necessary for the D90 and other cameras, as it is already set up by custom setting f4.

Now you’re all set up and ready to go.

How to use the AF-On technique in the field

To emulate single-servo mode (focus/recompose/shoot)

  1. Place the active AF point on your subject
  2. Press the AF-On button to acquire focus
  3. Release the AF-On button to lock focus
  4. Recompose and shoot

To focus continuously on a moving subject

  1. Place the active AF point on the subject
  2. Press the AF-On button
  3. Keep the AF-On button pressed to track focus while simultaneously pressing the shutter release
  4. Remember to initiate the VR system (if your lens supports it) by half-pressing the shutter button prior to releasing the shutter.  Remember, VR takes about a half-second to stabilize, so you’ll want to anticipate your subject.

Now that you understand how to use the technique, you’ll want to spend some time practicing.  It usually takes about a day of shooting in the field to get used to the new technique.  Once you know how to use it, the AF-On only method of focusing will help you get more “keeper” shots.

150 thoughts on “Mastering the AF-ON Technique with Nikon DSLRs”

  1. The D4 works the same way as the D3. The difference is that in the D4 and D800 AF-ON activates VR, too.

  2. Can you use this technique for shooting HDR images and if so would you have to keep the AF/ON button depressed until all images in the sequence have finished or not?. Could you walk me through the steps for using this technique when shooting an HDR sequence.
    Thanks

  3. When using the AF-On technique… What should I have my focus points set to? 39points, 9points, single point, ect. I have a D7000.
    Thanks, Kenny

  4. Kenny-
    Use whatever is appropriate for the subject at hand. I use single-point whenever possible as it is the most responsive. However, if you’re tracking a moving subject and are having a hard time keeping the AF point on it, switch to one of the dynamic modes. Always try to use the fewest AF points as possible.

  5. Thank you Jason, excellent description and instructions on camera set-up. I have been trying to figure out how to do precisely what you clearly described.

  6. excellent tutorial, it helped me a lot
    I’m using a simpler camera (D80) and it works great. AF-C priority goes automatically to release, whilst AF-S priority goes to focus.
    Using AF-S if you focus, recompose and try to shoot while the AF point is not on focus it will not shoot (Error r06 ). This may be used as a ‘focus trap’, for example for shooting moving subjects, however for moving subjects I still prefer the technique you described (AF-C).

  7. Great post, but I still don’t know how to set my D7000 as in point #5 (Find the custom setting for AF Activation (a5 on the D3s) and set it to AF-On Only. This step is not necessary for the D90 and other cameras, as it is already set up by custom setting f4. ) I think AF-ON does not exist on it. Can you help me?
    Thanks,

    Mike

  8. Finally, I got it. I have D7000 and the only button I could program as AF-ON is the back button (AF-L, AE-L). I wanted to do it with the Fn button, but I didn’t see the option AF-ON. Then I read one of the sites mention on this blog (http://everydayelementsonline.com/2011/11/how-to-back-button-focus/) and found the option. Great technique. I tried a few shots – not complicated and very reliable. I<ll try more tomorrow, outside, but I am sure I'll continue to use it. Thanks!!!

    Mike

  9. Thanks for the tip. Shooting a ballet recital this weekend and I think this will be a big advantage for stage shots.

  10. great video covered most apart from what setting do you leave your focus in SPOT or AREA or do you have to change that as well

  11. I use single-point AF unless I can’t keep the spot on a moving subject. Always use the minimum # of AF points that you can get away with for your needs.

  12. Hi- I have the d5100. I set it up using the ae-l/af-l as my AF-ON button and switched my AF priority to release. So now should my camera work as you just described? If so then that is terrific! Thanks

  13. Thank you for the video. I learned a lot! Just one part I couldn’t quite fully grasp if you don’t mind clarifying regarding setting it on Release priority. Won’t you get a lot of out-of-focus shots if you use that setting? Thank you.

  14. Hi Jason,
    I set this on my D800 but I hope I am doing this right. If I use it for a portrait shot, I use the AF-ON button set my focus point and release the AF-ON button, how come the green dot doesn’t show when I release to take picture? Am I doing something wrong? I understand for tracking a moving subject I must keep it pressed ( AF-ON) button. I set it up like in the video, is it different for the D800?
    Thanks,
    Rich Ramirez

  15. I recently upgraded from a D7000 to a D800. Now that I have a dedicated AF-ON button, I have a question. If I keep the default setting “Shutter/AF-ON,” how come after I hit that button and release it …. press the shutter halfway, it refocuses? What’s the difference between the two settings? …… Shutter/AF-ON vs AF-ON only? I assume that the AF-ON only is very similar to how I would use it on the D7000. But why would Nikon not just have the settings as Shutter Only and AF-ON Only? Any information would be greatly appreciated. Thanks :)

  16. The default setting allows both shutter and AF-On buttons to activate AF. That means, unless you disable the feature in your custom settings (to use AF-ON only), then every time you half-press the shutter, the camera will try to focus.

  17. But when I have it set with the default settings, hit the af-on button & release it, recompose, and push the shutter halfway before taking the shot, it refocuses. This is if I have the setting at Shutter/AF-ON. What am I doing wrong? This is on a D800. Thanks. Hope I’m making sense.

  18. Terrific technique which I have now mastered with my d7000. Thanks. Please clarify if this system works when I use a remote release with my camera on a tripod.

  19. I’m pretty sure you can, but you’ll need to check your manual about customizing the function of the AE-L button to be used as AF-ON.

  20. Hey Jason,

    Brilliant video, you’ve improved my understanding of how auto-focus works. I haven’t got to try it yet but have a football game tomorrow to shoot so will then. Soon come!

    I have one question. I know i should use a single AF point to track a player. Butf he runs sideways & i don’t keep up can the AF be set to automatically track him?

    Thanks,
    Tom

  21. Hi Jason,
    Can I use BBF with a 105 VR lens? I am really shaky and the VR has made a huge improvement in the sharpness of my photos especially the close ups. I shoot with a Nikon D200 and at iso 1600 to increase depth of field. There is a slight increase in noise at this setting, but not a problem for my work and my editor will take care of it if necessary.

    Really appreciate any help on this subject.

    sps

  22. You can use it with ANY lens. With the D200, you’ll need to half-press the shutter release to activate the VR system.

  23. Oh, my goodness. I’ve come across this function/process for the first time twice this week. Found your video this morning featured on a blog that had a 3-step instruction on how to configure camera settings. Gave it a whirl in about 3 minutes, and, like I’ve read that others do, I’m never going back. I set it up on a D90, so the video demo regarding buttons and specific setting locations wasn’t overly helpful but the rest of the video was very explanatory. Thanks so much. Well-made video with great instructions regarding setup and purpose, etc.!
    -Abby

  24. Is there any way to disable that AE/AF button’s photo lock/protect feature? d5100

    I missed some shots frustrated by this, while having to tap/release the shutter button or turn the camera off every time after a shot to reset the autofocus and exposure and to be able to shoot again.

  25. Mark-
    How do you have your AE/AF-L button set? If it’s set as AF-ON, then it should disable the AE-Lock feature.

  26. I shoot mostly sports with a Nikon D3. This technique is perfect for sports shooters. However, I am going to do some landscapes using a tripod and remote release. Will the remote release work the same as using the shutter release button or will it try to refocus.
    Thanks

  27. Carroll-
    The remote will not activate AF if you are in AF-On only mode. I find this incredibly useful for my landscapes where I like to focus on one spot, meter off another, and take the shot with my release cable.

  28. Jason. Excellent procedure in setting the AF-ON button for the D3S.
    I have a D300s & D7100 and have set their buttons up given your sample direction.
    Suggest you provide a video for the D7100 & D800 series for fans moving up to these models….?. One needs more techniques for great focusing and shooting.

  29. Jason – great video explaining how to take advantage of the AF-ON. I was never sure if the focus can/will be locked after pressing the AE/AF-L button(I have D5100 thaT i programmed this button to AF-ON) and recomposing the frame.. After watching your video, I realized the key is knowing when to release your thumb from the button, before recomposing…IT WORKS!

    One question I have around focusing: I recently bought AF-S DX 35mm/f1.8 lens(great value lens) and I can take nice shots of one person in the frame, with great blur in the background. But when trying to take picture of 2 people in a frame, and still trying to get blurred background, I find running into focus issues. Most of the times, one of the persons is unintentionally blurred. Appreciate any insights on how to get both of them in focus BUT still able to get the blur background?

    Settings I used: 1/30, f1.8, ISO 500 , AF-ON, Single point area, center weighting metering (had to shoot this indoors at night)

  30. Jason. Thks for sharing you tips. I tried it on my Nikon D7000. and on continuous mode the Speed is a bit slower. Is this normal? Thanks.

  31. That’s not a defect, that’s the issue with shallow depth of field. Try stopping down to f/4 to get the people in-focus while still blurring the background. Make sure both people are in the same plane of focus.

  32. Jason,

    I am so glad I found your video! I have been hearing about BBF and didn’t have a clue about how to use it. I have a D300 and D200 and am eager to try this out. I am confused about its use when using a tripod with or without VR. So how should I set up when using a tripod and cable release? I’ll be going to Yellowstone and want to get my shots in focus on or off my tripod. Thanks. You are a big help to Nikon and NIK users. Thanks.

  33. Hi,
    I own a D90. Do you know why I cant use this technique with AF-S? After recompose the camera wont let me shoot….Sorry in case I missed the answer in the thread.
    Regards.

  34. Juan-
    you need to use AF-C for this to work, using “release priority mode.” That’s why your camera won’t shoot; it’s in “focus priority” mode with AF-S.

  35. Thank you so much for your help. I am a newbie here with a Nikon D7100. I have 2 questions that I hope don’t sound too absurd. The first is what settings can we use this in such as manual? Aperture Priority? Shutter Priority? and auto? I’m assuming just auto. The second is when you say to look through the camera and find your active focus point. How would I tell where that is? I have it set up on my AEL Lock button since it’s the D7100 and I don’t have an AF on. When I look through the camera what is the next step, do I then press the AE Lock (AF) button to locate my active focus point? Can’t seem to find where my active focus point is at. Also, when I set it up in the menu at one point it has an option for AF on but in the video I believe it said the AF on Only button. Is it actually supposed to say “only” as there is an option that says AF Lock Only . Well I guess that was 3 questions.

    Thanks from an embarassed newbie.

  36. Mary-
    The technique I describe works in any Exposure Mode (Aperture, Shutter, Program), but you need to set Autofocus to use something other than “Auto Area.” Try single point AF mode.

    The active focus point should be visible when you half-press the shutter release.

  37. Hi Jason,
    Thanks for the illustration of the technique.
    With this you need to set Metering to Matrix Mode, right? I usually use Spot Metering therefore create a wrong exposed photos when locking focus with AF-On and recompose.

  38. You can use any metering mode, but you are correct that with spot-metering, the active AF point is also the spot metering point.

  39. I had tried this technique for 6 months now and very satisfy. Then I realize, it won’t trigger AF-assist beam from my SB-900 while I’m shooting outdoor at night while there aren’t much light on the subject or in a darker room where the camera won’t focused. Do you had any suggestion or advice in these kind of situation? How I did last time is by switch the AF to AF-S.

  40. Salim- If you need to use AF assist lamps, then AF-S (single-servo mode) is your only recourse.

  41. Jason, have used your idea for some time on my D700 but just noticed on my D800 that if I track and then release the AF button and recompose, the View Focus point on the recorded image shows at the recomposed point of the image ie when shutter fires) and not at the point in the scene where the button was released although focus is at the button release point..
    Is that correct?
    Thank you.

  42. I believe the camera will show the active focus point, not the part of the scene that was focused on.

  43. Hi Jason!

    I have a Nikon D4 and my longest lens is the Nikon 70-200mm 2.8 VR II.

    I want to use your suggestions as I like to shoot that way,using the AF/ON back button to focus and the shutter button only to take the photo.

    My problem is that when I put my selected square light on the subject the light is red
    and never turns ” GREEN” to confirm focus. Another thing is:
    Example: portrait of my wife.

    1) I select the camera to focus in “one eye” by pressing the AF/ON back button. ( either on Single or Continuous mode.

    2) Release the AF/ON

    3) Recompose and shoot.

    BUT when I check on camera to see the area where my focus point was set (the eye) in fact it shows that the camera focused elsewhere as I recomposed. So in fact the camera did not locked on the eye.

    Like I said the green focus light never shows.

  44. When focus is locked, the software shows the location of the active focus point, not the point where it was focused on. This is normal.

Leave a Reply

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

186,897 Spambots Blocked by Simple Comments

HTML tags are not allowed.