LV auto focus without shooting

[sxs9825]

Can I set up the camera so I can autofocus by touch screen but not take a shot?

Right now it only seems to work to autofocus if the camera takes a shot.

[jrhoffman75]

You didn't state which camera. On some models (maybe all) you can toggle between touch shutter on or off.

[sxs9825]

Sorry 80d

I know that I can toggle the shutter on/off, but it seems to also turn on/off the focus with it.

[jrhoffman75]

If you disable touch shutter then focus and exposure are controlled by main shutter button. Touch screen where you want to focus and half press shutter button.

[sxs9825]

Thanks for the prompt replies.

If I do that, then what is it using to focus?

My understanding is that when you use live view focusing that it is using contrast detection. When using the view finder then it's phase detection (not that I know how that works yet).

If I am in live view but use the shutter to focus which one am I using to focus with?

[jrhoffman75]

You are using Live View focusing in either case - touch or button. All that changes is how focus is activated.

[BurnUnit]

I think the choice of focusing mode is all a matter of whether or not the mirror is in the locked-up position. Live View only works when the mirror is in the locked-up position.

[sxs9825]

Good to know.

Makes sense that the mirror being up would make it work that way.

Thanks!

[jrhoffman75]

How pahse detection works:

https://fstoppers.com/education/excellent-explanation-how-phase-detection-autofocus-works-269078

[sxs9825]

Thanks. that was interesting.