I haven't used live view much, but need to use to for a self service "photo booth" for an event, where I am using the HDMI output so that guests are able to see the composition of the shot and pose.
I have the camera, a Nikon D7100, set to face focus mode. From the view on the screen it appears to work well and shows green rectangles around faces (which I believe means in focus).
However when the shutter button is pressed (either on the camera, or with remote control) the camera takes a second to refocus before taking the photo.
Is there any setting that can be changed to just use the focus currently seen in live view, and avoid the time penalty to refocus?
Edit: I am using a Nikon d7100 with a AF-S Nikkor 35mm 1:1.8g prime, I don't have the final setup yet but tests have been done in a bright room (I do note that the live view won't continuously autofocus unless there is a certain brightness)