Canon A640PS Digital Camera User Manual


 
43
Shooting
The camera automatically sets the shutter speed and aperture
value to match the brightness of the subject.
zWhen a correct exposure cannot be obtained, the shutter speed and
aperture values are shown in red on the LCD monitor when the shutter
button is pressed halfway. Use the following shooting methods to
obtain the correct exposure and make them show in white.
When you set the shutter speed, the camera automatically selects
an aperture value to match the brightness of the subject. Faster
shutter speeds allow you to catch an instantaneous image of a
moving subject, while slower speeds create a flowing effect and
allow you to shoot without a flash in dark areas.
Program AE
Shooting Mode
- Using the flash
- Changing the ISO speed
- Changing the metering method
You can change the combinations of shutter speeds and
aperture values without altering the exposure (p. 53).
Setting the Shutter Speed
Shooting Mode
zIf the aperture value is shown in red, the image is
underexposed (insufficient light) or overexposed (too much
light). Use the or button to adjust the shutter speed
until the aperture value shows in white.
zThe nature of CCD image sensors is such that noise in the
recorded image increases at slow shutter speeds. This
camera, however, applies special processing to images
shot at shutter speeds slower than 1.3 seconds to
eliminate the noise, thereby producing high-quality images.
(However, a certain amount of processing time may be
required before the next image can be shot.)