V. INCOMPARABLE EOS AUTOFOCUS, NOW EVEN BETTER
19
AF Start Button
AF Point Selection
Focusing Computation
Also, the secondary image-forming lens is optimized for the f/5.6 and f/2.8 light flux by
having a different surface shape for the respective light flux entering the lens. The top and
bottom light flux is compatible with f/5.6, while the left and right light flux is compatible
with f/2.8. The rear side of the secondary image-forming lens features a newly-developed
aspherical surface compatible with f/2.8 lenses.
The EOS-1D Mark III has a new AF Start (AF-ON) button that
can be used to execute AF and metering. We know that many
pros using the EOS-1D series cameras have set C. Fn 04-1 to
use the AE lock button for AF. The technique is called
"autofocus with your thumb" or “back button focus.”
The 1D Mark III now provides a new AF start button dedicated to AF. Pressing the AF
start button executes AF and metering. C. Fn IV-1,3 (AE lock/me AF start) is
equivalent to C. Fn 04-1 in previous cameras.
The AF points can be put to work in several different ways. First, the AF points can be
automatically selected by the camera from among the 45 points. Second, any one of 19
can be selected manually by the user. With C. Fn III -9-1/2, the manually-selectable AF
points can be limited to 9 inner or outer AF points (including the center AF point). The AF
point selection procedure is the same in either case. Press the AF selection button, then
turn the Quick Control Dial or Main Dial to select the desired AF point. Pressing the
Multi-Controller will select the center AF point. With the center AF point selected, pressing
the Multi-Controller will set automatic AF point selection.
As with the EOS-1D Mark II
N
, two separate CPU processors are used, one for AF processing
(including lens driving) and one for the camera. To attain 10 fps with AI Servo AF, the AF
CPU and camera CPU are both the latest microcomputers (AF CPU: 48 MHz, 32-bit RISC;
Camera CPU: 40 MHz, 32-bit RISC). The computing speed is 3 times faster than the
1D Mark II
N
's CPUs.
Main Dial
Quick Control Dial
C.Fn III -9-0: 19 points
C.Fn III -9-1: 9 points (Inner)
C.Fn III -9-2: 9 points (Outer)
Automatic selection
Automatic selection
Automatic selection
Automatic selection
Automatic selection
Automatic selection
