Canon EOS-1D X Mark III Advanced User's Manual page 74

Holding the Camera
To obtain sharp images, hold the camera still to minimize camera shake.
(1) Horizontal shooting
(2) Vertical shooting
1. With your right hand, hold the camera firmly by the camera grip.
2. With your left hand, support the lens from below.
3. Rest your right index finger lightly on the shutter button.
4. Rest your arms and elbows lightly against the front of your body.
5. To maintain a stable stance, place one foot slightly ahead of the other.
6. Hold the camera near your face and look through the viewfinder.
Note
To shoot while looking at the screen, see Live View Shooting.
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