Canon MARK IV User Manual (en)

Basic Operation
The shutter button has two steps. You can press the shutter button 
halfway. Then you can further press the shutter button completely.
Pressing halfway
This activates autofocusing and 
automatic exposure metering that sets 
the shutter speed and aperture.
The exposure setting (shutter speed and 
aperture) is displayed on the top LCD 
panel and in the viewfinder (9).
Pressing completely
This releases the shutter and takes the 
Preventing Camera Shake
Camera movement during the moment of exposure is called camera 
shake. Camera shake can cause blurred pictures. To prevent camera 
shake, note the following:
• Hold and steady the camera as shown on the previous page.
• Press the shutter button halfway to autofocus, then press the 
shutter button completely.
Shutter Button
Pressing the <p> button will be the same as pressing the shutter 
button halfway.
If you press the shutter button completely without pressing it halfway first 
or if you press the shutter button halfway and then press it completely 
immediately, the camera will take a moment before it takes the picture.
Even during the menu display, image playback, and image recording, 
you can instantly go back to shooting-ready by pressing the shutter 
button halfway.