Exposure can be altered from the value suggested by the camera by setting both shutter speed and aperture to values other than A (if A is currently selected for shutter speed, press the dial lock release while rotating the shutter speed dial).
M will appear in the display.
Shutter speed can also be adjusted in increments of 1/3 EV by rotating the front command dial.
Exposure Preview
To preview exposure in the LCD monitor, select an option other than OFF for SCREEN SETTING > PREVIEW EXP./WB IN MANUAL MODE.
Select OFF when using the flash or on other occasions on which exposure may change when the picture is taken.