Trying to understand touch screen focus on the 5d IV

I would like to take advantage of the DPAF of the 5D IV, but I have some questions.

Do I have to have AF enabled on half-shutter press to be able to use touch to focus? I only use back button focus, and it seems like this prevents me from using the touch screen.

If I do use live view and select the focus point with the touch screen, then, once I hit the focus button, is it using DPAF, or is it reverting back to traditional phase detect auto focusing that is subject to lens micro-adjusting?

Yes you have to put focus back on the shutter button. Phase detect AF cannot occur while live view is in effect, showing you the scene. The mirror would have to flip back down to allow phase detect, which would black out the display.

Yup only works when shutter is in normal mode.

TeamSpeed wrote in post #18322315
Yes you have to put focus back on the shutter button. Phase detect AF cannot occur while live view is in effect, showing you the scene. The mirror would have to flip back down to allow phase detect, which would black out the display.

Yes. Dumb question on my part. I already know that phase detect can't happen with the mirror up. I wasn't thinking.

I still don't understand the relationship between having to enable shutter button focus to get touch focus to work.
Seems like two independent features to me.

I am not sure either, but the same issue arises with remote control via wireless too. You would think they could have an override option for screen or remote shooting.

Ah, this thread reminded my why I never settled on using BBF. I just use remote shooting too often, vs the benefits of BBF.

I will say that if memory serves, you don't have to disable BBF and enable shutter release focus, you only need to enable shutter release focus. Both can be active at the same time.

Seems like a good example of where the custom shooting modes (C1 - C3) option could be useful ... one mode set up for BBF, another for shutter button focus? Only if you actually like BBF for general shooting, of course. There might be some other settings that would combine well for shots taken using remote release.