5D MkIV - Back button focus & AI Servo

[jbpooler]

I take mainly landscape photographs, but am trying to set up my 5D MkIV for AI Servo using the back button focus.  I have watched several YouTube videos from wildlife photographers, but for some reason??? I am unable to get the desired results.

Objective:  When holding the back button down, I would like to have the lens continuously focus (AI Servo) on a moving object (wildlife, kids, etc).  At the moment, the lens adjusts focus only ONCE when I depress the back button.  If the subject moves, the camera only adjusts focus when I press the back button key again. 

When I set the shutter button for the factory default operations (i.e., half depress the shutter button to focus), the lens constantly adjusts focus as the subject moves. HOW do I get the back button to achieve the same effect????  It seems like it should be a simple setting... but I can't seem to find it.  BTW, I'm not new to cameras or Canon or photography.  Just frustrated.  TIA.

[Waddizzle]

The default, factory setting of the [AF-ON] button should have done what you wanted.  Go to the Custom Controls screen, the one where you can program the control buttons, and select the [RESET] opton.  For most BBF configurations, people will disable focusing on the [SHUTTER] button.

Personally, I started off using BBF with AI Servo that way on a 7D2.  But after following a suggestion, I tried the exact opposite.  I began using the {AF-ON] button as an {AF-OFF] button when using AI Servo with Continuous Drive and Zone AF.  Auto Focus always starts with the center AF point, and track the subject to surrounding points.  

If lose the subject, I can press the [AF-OFF] button to restart AF tracking from the center AF point.  It is also effective for when an obstruction comes between me and the subject.  A quick tap pauses AF, while a longer press resets AF tracking back to the center Af point.

[jbpooler]

Waddizzle,

Thank you for your suggestion.  Resetting to factory default cleared the problem.  Now the AI-SERVO mode is fully functional with continuous focus adjustment when holding the back button.

Thanks again.

[ebiggs1]

You need to reset the camera. You don't know where it is for sure right now.  Clear all settings and clear all custom settings and start over.

" I began using the {AF-ON] button as an {AF-OFF] button when using AI Servo ..."     When I use this feature, which is very rarely, I do the same. I am too old fashion for too many of the gimmicky new fangled features.

[Waddizzle]

“At the moment, the lens adjusts focus only ONCE when I depress the back button. If the subject moves, the camera only adjusts focus when I press the back button key again.”


Make sure you are in AI Servo mode, not One Shot mode.