Canon EOS-1D Mark IV - Manual (Page 98)

EE Selecting the AF Point
Selecting with the Dial
To select a horizontal AF point, turn
the dial.
To select a vertical AF point, turn the
<
0
> dial.
If all the peripheral AF points light up,
automatic AF point selection will take
effect.
Q • With [.B.C.Fn III -10: Selectable AF point], the selectable AF points can
be limited to 19 or 11 AF points or to the inner or outer 9 AF points
(p.223).
• With [.ff.C.Fn III -8: AF expansion w/selected pt], you can change the
AF expansion to the left/right AF points, surrounding AF points, or all 45
AF points (p.222),
• If you use a super telephoto lens equipped with an Image Stabilizer and
AF stop button, when [.fflC.Fn III -6: Lens AF stop button function] is
set to [7: Spot AF], spot AF will be possible (p.220).
•
By registering the AF point you use frequently, you can switch to it
instantly by setting C.Fn III -11-1/2 (p.224) or C.Fn III -6-6 (p.220).
• If focus cannot be achieved with the external, EOS-dedicated Speedlite’s
AF-assist beam, select the center AF point.
Lens’ Maximum Aperture and AF Sensitivity
With the EOS-1 D Mark IV, higher precision AF is possible with a
maximum aperture brighter than f/2.8 on a lens or when combined with
an Extender,
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