Canon MARK III EOS-1 DS Instruction Manual page 37

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.
< > Using the Main Dial for Selecting
6
Pressing completely
This releases the shutter and takes the
picture.
(1) After pressing a button, turn the
<6> dial.
When you press a button, its function remains
selected for 6 seconds (9). During this
time, you can turn the <6> dial to set the
desired setting. When the function turns off or
if you press the shutter button halfway, the
camera will be ready to shoot.
Use the dial to select or set the
shooting mode, AF mode, metering
mode, AF point, ISO speed, exposure
compensation when the <O> button
is pressed, or memory card.
(2) Turn the <6> dial only.
While looking at the viewfinder or top
LCD panel, turn the <6> dial to set the
desired setting.
In this way, you can set the shutter
speed, aperture, etc.
Basic Operation
37