Quickly toggle Ai Servo Focus on the Canon 5D Mark III - Digital Photography School

Quickly toggle Ai Servo Focus on the Canon 5D Mark III

Here’s a quick tip for Canon 5D MkIII users.

Canon EOS 5D MkIII with EF 50mm f/1.2L

Canon EOS 5D MkIII with EF 50mm f/1.2L

If you don’t use this camera, this tip probably isn’t very helpful for you. Instead you might be interested to read about how I shot the above photo. Also, I recommend skimming through your camera manual to see what customizations are available. Customizing your camera’s button configuration can help taylor the camera to your shooting style.

With the 5D Mark III, Canon added the ability for users to change the function of several of the buttons on the camera body. In addition to this new functionality, Canon also moved the Depth of Field (DoF) preview button. It’s now on the left side of the lens, in approximately the 8 o’clock position, as you look at the camera’s front.

The new location of the DoF preview button and the ability to assign different functions to the standard buttons brings an interesting new shooting option. As I rarely use the DoF Preview Button, I’ve changed it’s function to toggle Ai Servo Focus when held down. To re-assign the DoF Preview Button to toggle Ai Servo focus mode on the 5D MkIII follow these steps:

1. Navigate to menu C.Fn2:Disp/Operation

Step 1

Step 1

2. Select the DoF Preview Button from the list of buttons

Step 2

Step 2

3. Change the button’s function to ONE SHOT AI SERVO

Step 3

Step 3

This customization allows me to stay in Single Shot AF mode, and toggle Ai Servo focus with my right ring finger if my subject starts moving. This is an incredibly flexible way to handle moving subjects and I like being able to toggle between two AF modes without moving the camera from my eye.

Give this a try and let me know how you like it. It took me a couple weeks to train myself to use my ring finger to toggle Ai Servo, but now that I’m used to it, I love shooting this way. As always, you can find me on Facebook.

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Jason Weddington is passionate photographer and the creator of PhotoQueue.com, a service that helps photographers maintain their online presence by scheduling uploads to Flickr and 500px. PhotoQueue will soon add support for Facebook, and Tumblr. You can connect with Jason on Google+, Facebook, or Flickr. Jason is also an Associate member of the American Society of Media Photographers (ASMP).

  • jay

    Thanks for the Tip – also works on the 6D.

  • Fabio F

    This works on 6D also.

  • http://eigsti.com Greg Eigsti

    Jason, thanks for the reminder! Like you I rarely use DOF preview and keep meaning to make this change. Last night as I drifted off into sleepy land I thought “tomorrow, tomorrow is the day to make this change”. Of course I forgot all about it until I saw your post. ;) So THANK YOU!

  • http://jasonweddington.com Jason Weddington

    Jay, Fabio thanks! It’s good to know that this works on the 6D too.

    Greg – you’re welcome, glad this post reminded you! Shooting this way has really been useful for me.

  • http://www.willphillipsphotography.com/ Will Phillips

    Also worth noting that this works on the 7D!

  • http://www.davidandkara.com David + Kara Wedding Imagery

    This makes me want that thing so much more! Great tip!

  • Rolando

    While it does work on the 5D, the DoF button is not as easy to get to as on the 5D3.

  • Kari Korpihete

    This is good! I adjusted the focus AF-ON key, this is also good.

  • Andrew

    If you use custom function 4 (and you do right?) for back button focus, you can just stay in AI servo mode all the time. Use a short press of the back button to obatin focus just like single shot, keep it held down for true AI servo focus. Easy.

    Learn to use your DOF preview button properly and it will reduce the amount of time you spend chimping your LCD (when you should be shooting) asyou wont need to check what effect the aperture you chose did to your shot.

    Obviously shoot whatever way feels right to you, but the above will get you the same effect as mentioned in the post with less complexity and fee up your depth of field preview button for the purpose its for.

  • http://www.robyngphotography.com Robyn

    Yes, thank you – never use the DOF button on any camera! Going to check if I can do it on the 7D :)

  • Paul

    @ Andrew – this is true, however if using a Speedlight, you won’t get AF-assist beam in AF-Servo mode as it only fires in one-shot :)

  • http://jasonweddington.com Jason Weddington

    Andrew – Thanks for the suggestion about back button focus. I’ve tried that but couldn’t get used to using my thumb to activate AF. Though I do know other photographers who shoot this way.

    I don’t find the DOF preview to be very useful through the viewfinder on the 5D mkIII, it seems to show significantly more DOF than there actually is in the shot. Over time I’ve gotten to know my lenses and I know what apertures I like on various lenses for common shooting scenarios.

  • Andrew

    That’s afair call. It is the focus screen that creates the deeper depth of field in case you didn’t know. :)

  • http://www.fotografia.pro.br Rafael Fischer

    Hi!

    This was possible since the launch of the 7D :-)

  • http://www.photoshah.com cortlander

    You can also customize the ‘SET’ button which by default is available.

    I find it useful to use the SET button to change the ISO without having to take my eyes off the viewfinder.

  • Andrew

    You have an iso button on the top of your camera with a “nub” on it you can feel with your finger, isn’t that easier? A good use for re-assigning the set button I have found is for flash exposure comp. Nikon use the flash button not just to trigger the flash on your camera, but if you hold it down, it does FEC too, something that’s been missing on Canon’s for a long time. Using the set button for that means no more digging around in menues.

  • http://www.photoshah.com cortlander

    No, try it in real use, and you will find it far, far more convenient to push SET and wiggle the top wheel. When I look through the view finder, I do want to set the lowest possible ISO while keeping the aperture/shutter manageable. With this combination, it is easy.

    And seem there are others who do the same, as I found out on dpreview:
    http://forums.dpreview.com/forums/thread/3398160#forum-post-51032510

    Works for me, but to each his/her own.

  • http://www.photoshah.com cortlander

    Andrew, I do use back button focusing. However, just pushing the back button does not give you AI-Servo capability. You have to be in the AI-Servo mode to be able to use the ‘Rate’ button to set Tracking Sensitivity, Acceleration/Deceleration Tracking and AF Point Auto Switching.

  • Duke

    It’s interesting Canon is just now allowing customization of the buttons. No need for this solution for Nikonians. Holding the AF button down whilst shooting accomplishes the same task.

  • http://www.tyfaruki.com/ Ty

    This works on the 6D too. Fantastic camera!

  • Marv

    Why not just set the auto focus mode to Al Focus?

  • aac

    Another button I like to use on my Canon 5D mk III is the M-Fn button on the side of the main dial. I found it most useful to set if to AE LOCK and HOLD especially when I want to take several shots with the same exposure value.

  • http://jasonweddington.com Jason Weddington

    aac – great tip, thanks! I’ll try that when I shoot a series of shots for a stitched pano.

Some older comments

  • Jason Weddington

    April 1, 2013 04:21 am

    aac - great tip, thanks! I'll try that when I shoot a series of shots for a stitched pano.

  • aac

    March 31, 2013 11:40 am

    Another button I like to use on my Canon 5D mk III is the M-Fn button on the side of the main dial. I found it most useful to set if to AE LOCK and HOLD especially when I want to take several shots with the same exposure value.

  • Marv

    March 29, 2013 11:46 am

    Why not just set the auto focus mode to Al Focus?

  • Ty

    March 25, 2013 01:30 am

    This works on the 6D too. Fantastic camera!

  • Duke

    March 23, 2013 12:51 am

    It's interesting Canon is just now allowing customization of the buttons. No need for this solution for Nikonians. Holding the AF button down whilst shooting accomplishes the same task.

  • cortlander

    March 22, 2013 11:20 pm

    Andrew, I do use back button focusing. However, just pushing the back button does not give you AI-Servo capability. You have to be in the AI-Servo mode to be able to use the 'Rate' button to set Tracking Sensitivity, Acceleration/Deceleration Tracking and AF Point Auto Switching.

  • cortlander

    March 22, 2013 10:39 pm

    No, try it in real use, and you will find it far, far more convenient to push SET and wiggle the top wheel. When I look through the view finder, I do want to set the lowest possible ISO while keeping the aperture/shutter manageable. With this combination, it is easy.

    And seem there are others who do the same, as I found out on dpreview:
    http://forums.dpreview.com/forums/thread/3398160#forum-post-51032510

    Works for me, but to each his/her own.

  • Andrew

    March 22, 2013 06:01 pm

    You have an iso button on the top of your camera with a "nub" on it you can feel with your finger, isn't that easier? A good use for re-assigning the set button I have found is for flash exposure comp. Nikon use the flash button not just to trigger the flash on your camera, but if you hold it down, it does FEC too, something that's been missing on Canon's for a long time. Using the set button for that means no more digging around in menues.

  • cortlander

    March 22, 2013 03:03 am

    You can also customize the 'SET' button which by default is available.

    I find it useful to use the SET button to change the ISO without having to take my eyes off the viewfinder.

  • Rafael Fischer

    March 21, 2013 05:09 am

    Hi!

    This was possible since the launch of the 7D :-)

  • Andrew

    March 19, 2013 08:13 am

    That's afair call. It is the focus screen that creates the deeper depth of field in case you didn't know. :)

  • Jason Weddington

    March 19, 2013 07:47 am

    Andrew - Thanks for the suggestion about back button focus. I've tried that but couldn't get used to using my thumb to activate AF. Though I do know other photographers who shoot this way.

    I don't find the DOF preview to be very useful through the viewfinder on the 5D mkIII, it seems to show significantly more DOF than there actually is in the shot. Over time I've gotten to know my lenses and I know what apertures I like on various lenses for common shooting scenarios.

  • Paul

    March 19, 2013 03:11 am

    @ Andrew - this is true, however if using a Speedlight, you won't get AF-assist beam in AF-Servo mode as it only fires in one-shot :)

  • Robyn

    March 18, 2013 04:54 pm

    Yes, thank you - never use the DOF button on any camera! Going to check if I can do it on the 7D :)

  • Andrew

    March 18, 2013 10:13 am

    If you use custom function 4 (and you do right?) for back button focus, you can just stay in AI servo mode all the time. Use a short press of the back button to obatin focus just like single shot, keep it held down for true AI servo focus. Easy.

    Learn to use your DOF preview button properly and it will reduce the amount of time you spend chimping your LCD (when you should be shooting) asyou wont need to check what effect the aperture you chose did to your shot.

    Obviously shoot whatever way feels right to you, but the above will get you the same effect as mentioned in the post with less complexity and fee up your depth of field preview button for the purpose its for.

  • Kari Korpihete

    March 18, 2013 04:09 am

    This is good! I adjusted the focus AF-ON key, this is also good.

  • Rolando

    March 17, 2013 03:38 pm

    While it does work on the 5D, the DoF button is not as easy to get to as on the 5D3.

  • David + Kara Wedding Imagery

    March 17, 2013 11:38 am

    This makes me want that thing so much more! Great tip!

  • Will Phillips

    March 17, 2013 11:02 am

    Also worth noting that this works on the 7D!

  • Jason Weddington

    March 17, 2013 06:30 am

    Jay, Fabio thanks! It's good to know that this works on the 6D too.

    Greg - you're welcome, glad this post reminded you! Shooting this way has really been useful for me.

  • Greg Eigsti

    March 17, 2013 05:44 am

    Jason, thanks for the reminder! Like you I rarely use DOF preview and keep meaning to make this change. Last night as I drifted off into sleepy land I thought "tomorrow, tomorrow is the day to make this change". Of course I forgot all about it until I saw your post. ;) So THANK YOU!

  • Fabio F

    March 17, 2013 02:02 am

    This works on 6D also.

  • jay

    March 17, 2013 01:47 am

    Thanks for the Tip - also works on the 6D.

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