Canon POWERSHOT SX100 IS User Manual page 21

88 I Shooting Using the Mode Dial
I AV Setting the Aperture []
[] See Functions Available in Each Shooting Mode (p. 222).
The aperture adjusts the amount of light entering through the lens.
When you set the aperture value, the camera automatically selects a
shutter speed to match the brightness.
Selecting a lower aperture value (opening the aperture) allows you to
blur the background and create a beautiful portrait. A higher aperture
value (closing the aperture) brings the entire range from foreground to
background into focus. The larger the aperture value, the greater the
range of the image brought into clear focus.
Aperture value
Shoot.
• If the shutter speed is shown in red, the image is
underexposed (insufficient light) or overexposed (too much
light). Use the control dial to adjust the aperture value until the
shutter speed shows in white (Safety Shift (p. 89)).
i_ Some aperture values may not be available with certain zoom
positions (p. 90).