T6i Backfocus Issue?

[AZR]

While shooting with a T6i and Canon EF 24-70mm 1:2.8 lens set to manual focus, the video image gets blurry about :07 into this clip. Is it a backfocus issue? https://youtu.be/UZi9jfASoz8

[MikeSowsun]

That is not a backfocus issue. The video starts out in focus but it looks like the camera tried to focus on the hand movements and then just lost focus for some reason.  

In a situation like that it would have been better to use AF to set the initial focus, and then switch to manual focus, since the subject remained at the same distance for the entire video. 

[AZR]

Mike, Re. "it would have been better to use AF to set the initial focus, and then switch to manual focus, since the subject remained at the same distance for the entire video." That's exactly what I did. Other suggestions?

[MikeSowsun]

The focus can not move by itself when in manual  focus.  You must have moved it manually or it was still in Auto Focus.

[AZR]

Mike, Re. "The focus can not move by itself when in manual  focus. (I agree) You must have moved it manually or it was still in Auto Focus. (Negatory)" Thanks for trying, but this issue has happened to another staffer 3x before.

[MikeSowsun]

It is rare, but the AF/MF switch might be defective or sticking.

[AZR]

Re. "the AF/MF switch might be defective or sticking." I'll have it checked out. Thanks, Mike!