1DX mark ii - problem with AI focus

[CW7647]

I'm puzzled.  When set-up in "AI Servo" and and using continuous shooting (at about 14 fps), as soon as I press the back button focus the drive changes itself to "one shot".  I suspect that this means that I am losing all the tracking benefits of AI Servo when shooting birds in flight for example.  This seems to happen whichever mode I'm in (manual, TV etc).  And it doesn't happen on my 5DsR.  So I must have something wrong in the settings on the 1DX mark ii, but cannot figure out what that might be.  All assistance much appreciated!

[wq9nsc · Accepted solution]

Is the drive itself changing from high speed to single shot or is the AF changing from servo to single shot?  It sounds like you have reassigned the button to switch between AI Servo and One shot.  See page 452 of the manual.

Rodger

[ebiggs1 · Accepted solution]

Reset the camera and start over.

[wq9nsc · Accepted solution]

Is the drive itself changing from high speed to single shot or is the AF changing from servo to single shot?  It sounds like you have reassigned the button to switch between AI Servo and One shot.  See page 452 of the manual.

Rodger

[CW7647]

Yes - it was the AF changing from AI Servo to One Shot.  Page 452 of the manual was the lead I needed, thank you.  I have no recollection of reassigning the AF-ON button to change from AI Servo to One Shot, but have now decativated it, and all is now fine.  As an aside, I never realised that a single button (the AF-ON in this case) could be given two roles at the same time.  I would have thought that having it set up for back-button focus that I wouldn't be able (inadvertently) to give it another role to perform at the same time!  We live and learn.  Thanks again.

[ebiggs1 · Accepted solution]

Reset the camera and start over.

[diverhank · Accepted solution]

You probably had the custom function set the back button focus to switch between Single shot and AI Servo.  Set the whole custom thing back to default and try again.

[CW7647]

Thank you - your diagnosis was correct! I have no recollection of reassigning the AF-ON button to change from AI Servo to One Shot, but have now decativated it, and all is now fine.  As an aside, I never realised that a single button (the AF-ON in this case) could be given two roles at the same time.  I would have thought that having it set up for back-button focus that I wouldn't be able (inadvertently) to give it another role to perform at the same time!  We live and learn.  Thanks again.