Page 77 - Friedman Archives

Focusing Essentials 77

This uses the same algorithms as Center Lock-On AF shown earlier, with
two key differences:
• It will only show you a tracking rectangle if it detects a face.

• You don't have to overtly tell the camera "This is my subject" and
press the center button. Instead, the camera locks onto the subject in
the usual way, and then uses that as a starting point for analyzing the
live view feed, identifying what the subject looks like, and then tries to
track it as previously described.
To see the difference in behavior, place your subject in the middle of the
frame (I told you to choose "Lock-on AF CENTER, for a reason!), press
the shutter release button halfway down, and then move the camera left and
right, up and down, just as before. Although the same subject tracking
algorithms are at work, it won't show you a white rectangle – however, you
CAN see the active focus points illuminate over your subjects, regardless of
where your subject moves to in the frame.

This can be a very useful tool in shooting sports, but as discussed earlier, it
will either work brilliantly or will quickly default to the "focus on the
closest thing in your defined focus area" if the camera can’t keep up with
your subject. Do some tests in your particular shooting conditions before
relying on it to shoot an important event.

3.4.1 OTHER FOCUS AREA CHOICES

So far we’ve talked about three of the MENU  3  Focus Area
settings: Center (one spot in the center of the viewfinder), Flexible Spot
(where you can choose any one of the 79 focus points), and Lock-On AF
(which is used in conjunction with any of the focus area choices and
augments the focus tracking algorithm by analyzing the live view feed.)

What do the other focus area choices do? A quick overview appears below,
and you can actually see the differences in Figure 3-7.

 Wide – Automatically choose from the camera’s 79 focus points
(Section 5.14.1)
 AF Area Points – If 79 is too many, concentrate on just the center 61
(Section 6.12)
 Center – Just use the one in the very center.