Canon EOS 30D Instruction Manual

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75
f
 Selecting the AF ModeN
Pressing the shutter button 
halfway activates the autofocus 
and achieves focus once.
X
The AF point which achieves focus flashes 
briefly. At the same time, the focus confirmation 
light <o> in the viewfinder is displayed.
X
With evaluative metering, the exposure setting 
(shutter speed and aperture) will be set when 
focus is achieved. The exposure setting and 
focus will be locked as long as the shutter 
button is pressed halfway. (p.79) You can then 
recompose the shot while retaining the 
exposure setting and point of focus.
While you press the shutter 
button halfway, the camera 
focuses continuously.
 
This AF mode is for moving subjects when 
the focusing distance keeps changing.
X
With predictive AF (p.76), the camera can 
also focus track a subject which steadily 
approaches or retreats from the camera.
X
The exposure is set at the moment 
the picture is taken.
One-Shot AF for Still Subjects
AF point  Focus confirmation
light
AI Servo AF for Moving Subjects
If focus cannot be achieved, the focus confirmation light <o> in the 
viewfinder will blink. If this occurs, a picture cannot be taken even if the 
shutter button is pressed completely. Recompose the picture and try to 
focus again. Or see “When Autofocus Fails (Manual Focusing)” (p.80).
In a Creative Zone mode (except <8>), the beeper will not sound even when focus 
is achieved. Also, the focus confirmation light <o> in the viewfinder will not light.