To open the Camera app
From the Home screen, tap the Apps icon
(in the QuickTap bar) > the Apps tab (if necessary) > Camera 
.OR
Tap Camera
from the Home screen.OR
While the screen is locked or off, touch and hold the Volume Down Key
(on the back of the
phone).
TIP!
If you’ve set your phone to use the Swipe unlock
method, from the Lock screen, simply press the Power/Lock
Key 
(on the back of the phone), then drag the Camera icon upward to open
the Camera app.