S
Selecting the AF Point
N
68
¡
Press the <
S
> and turn the <
6
>
or <
5
> dial.
¡
When you turn the dial, the selection will go
in the looping sequence shown on the left.
Under low-light conditions, the built-in flash fires a brief burst of flashes
when you press the shutter button halfway. This is to illuminate the
subject to enable easier autofocusing.
The EOS 20D will execute high-precision AF with lenses whose
maximum aperture is f/2.8 or larger.
With lenses whose maximum aperture is f/2.8 or larger
With the center AF point, high-precision, cross-type AF sensitive to both
vertical and horizontal lines is possible. With cross-type AF, vertical-line
detection is twice as sensitive as horizontal-line detection. The other
eight AF points are horizontal-line sensitive or vertical-line sensitive.
With lenses whose maximum aperture is larger than f/5.6
The center AF point is a cross-type AF sensor. The other eight AF
points are horizontal-line sensitive or vertical-line sensitive.
Selecting with the Dial
AF-Assist beam with the Built-in Flash
Lens’ Maximum Aperture and AF Sensitivity
¡
When looking at the LCD panel to select the AF point, note the following:
Automatic selection
, center
, right
,
top
¡
If focus cannot be achieved with an EOS-dedicated, external Speedlite’s
AF-assist beam, select the center AF point.
¡
In the <
3
> <
5
> <
7
> modes, the AF-assist beam does not light.
¡
The built-in flash’s AF-assist beam is effective up to about 4 meters/13.2 feet.
¡
In the Creative Zone modes when the built-in flash is popped up with the
<
I
> button, the AF-assist beam will be emitted if necessary.
69
After achieving focus, you can lock the focus on a subject and
recompose the shot. This is called “focus lock.” Focus lock works only in
the One-Shot AF mode.
1
Set the Mode Dial to a Creative
Zone mode.
2
Select the desired AF point.
3
Focus the subject.
¡
Move the AF point over the subject
and press the shutter button halfway.
4
Keep pressing the shutter button
halfway and recompose the
picture as desired.
5
Take the picture.
Focusing an Off-Center Subject
If the AF mode is AI Servo AF (or AI Focus AF set to Servo mode), focus
lock will not work.
Focus lock is also possible in Basic Zone modes (except <
5
5
5
5
>). In this
case, start from step 3.
