Canon EOS Rebel XTI - Manual (Page 52)

52
To obtain a good exposure of the subject, the camera sets the exposure
(shutter speed and aperture) automatically. This is called Program AE.
1
Set the Mode Dial to < d >.
2
Take the picture.
Focus the subject and press the
shutter button completely.
X The captured image will be displayed
for about 2 sec. on the LCD monitor.
Check the shutter speed in the viewfinder.
When you press the shutter button halfway, the bottom of the
viewfinder will display the shutter speed from 30" to 4000 (30 - 1/
4000 sec.). The darker it is, the lower the number (slower shutter
speed) will be. A slower shutter speed is more likely to result in
camera shake.
As a general rule, if the shutter speed is slower (lower number) than
the reciprocal of the lens focal length multiplied by 1.6 (For example,
if the lens focal length is 55mm, 55 x 1.6 is 80 so the reciprocal of 1/
80) is the minimum shutter speed required to prevent camera shake.
If the shutter speed is slower than this, either increase the ISO
speed (p.53) or use the flash (p.54).
The program can be shifted. (Program shift)
After pressing the shutter button halfway, turn the <6> dial to change
the shutter speed and aperture setting combination (program).
d : Program AE
Shooting Tips
In very low light or very bright light, the exposure setting
will blink when you press the shutter button halfway, as
shown in the figure. In low light, either increase the ISO
speed (p.53) or use flash (p.54). In bright light, decrease
the ISO speed.