70d LiveView - autofocus is on without shutter press

[Frank Kolwicz]

There's nothing in the manual that says it's supposed to work this way, changing focus when the shutter is not half pressed, but it does, it changes focus constantly for no apparent reason. Could there be a setup problem or is this likely in need of repair?

Camera does this with 600/4L and 1.4x and with 100-400L.

[Bob Atkins]

I think it will do that if you have continuous AF set. It's one of the custom functions.

[Frank Kolwicz]

Thanks, Bob,

I'll dive in there and look for it.

Frank

[Frank Kolwicz]

Thanks again, Bob,

The setting in the Live Shooting menu, 5th menu from the left and 3rd item down, "Continuous AF", was set to "enable", so I disabled it and now it works as expected. I wonder who finds the enabled  setting useful, when it is constantly AFing whether you're pointing at your subject or not. Certainly, for moving subjects that may dodge the AF sensor at any time and send the lens into a serious focus hunting delay it's a hassle and, if your subject is stationary, why use it?


Frank

[KeithB]

I would guess it is for video.