Shutter Release Button
Explanation: The shutter release button reacts in two steps:
- Slightly pressing it until you feel the first resistance will activate autofocus and exposure metering-
- Pressing it further will actually take a picture.
The exposure metering will be continuously adjusted as long as you hold the button pressed unless you have changed this in custom setting menu c1 Shutter-Release Button AE-L.
Tips: Use it frequently! But think beforehand 😉