topic Re: LV auto focus without shooting in EOS DSLR & Mirrorless Cameras

LV auto focus without shooting

sxs9825 — Mon, 26 Aug 2019 12:56:32 GMT

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.

Re: LV auto focus without shooting

jrhoffman75 — Mon, 26 Aug 2019 14:03:47 GMT

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

Re: LV auto focus without shooting

sxs9825 — Mon, 26 Aug 2019 14:27:49 GMT

Sorry 80d

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

Re: LV auto focus without shooting

jrhoffman75 — Mon, 26 Aug 2019 14:56:05 GMT

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.

Re: LV auto focus without shooting

sxs9825 — Mon, 26 Aug 2019 17:31:13 GMT

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?

Re: LV auto focus without shooting

jrhoffman75 — Mon, 26 Aug 2019 17:37:14 GMT

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

Re: LV auto focus without shooting

BurnUnit — Mon, 26 Aug 2019 17:43:50 GMT

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.

Re: LV auto focus without shooting

sxs9825 — Mon, 26 Aug 2019 18:01:06 GMT

Good to know.

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

Thanks!

Re: LV auto focus without shooting

jrhoffman75 — Mon, 26 Aug 2019 22:56:22 GMT

How pahse detection works:

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

Re: LV auto focus without shooting

sxs9825 — Tue, 27 Aug 2019 00:59:20 GMT

Thanks. that was interesting.