Sony Xperia1 IV User Manual page 188

Viewfinder appears.
If confirmation appears, follow onscreen instructions.

Alternatively, Press handset Shutter Key for one second or more, or Press Power Key twice, or in

Lock Screen, Touch & Hold
If there is no operation on Viewfinder, Photo Pro operation ends.

Tap to switch to "Video" Viewfinder (
5/11
Camera
to quick-activate Photo Pro.
)