Exposure / Focus / Metering / Drive modes (cont.)

Auto Focus modes

Mode Description

One Shot AF

In this mode a half-press of the shutter release activates AF and locks onto a single focus distance. The focus confirmation light (a dot on the viewfinder status bar) will be lit once a focus is achieved or blink of it can not be. You can, if you wish, recompose the shot while 'holding' the focus distance by keeping the shutter release half-pressed.

AI Servo AF

In this mode the camera constantly refocuses on a moving subject. If the subject is moving at a constant rate towards or away from the camera the focus system will 'predict' the new focus distance. This is especially successful when AF point selection is set to auto (the camera can use all 45 focus points to track a moving subject). In this mode the focus confirmation light only indicates if focus can not be achieved (it blinks).

  • C.Fn III-3 allows you to switch AI Servo auto focus between focus-priority (default), Tracking and shutter release-priority (with first and second priority options)
  • C.Fn III-2 can be used to change the AI Servo tracking sensitivity (standard, slow, moderately slow, moderately fast, fast) so that focusing isn't thrown off if (example) something crosses the path of the lens.
  • C.Fn III-4 lets you choose to give priority to the Main Focus Point or to Continuous AF tracking.

Metering modes

Mode Description


This metering mode is suitable for general shots and even those which are backlit. It uses the 21 metering zones in conjunction with the current AF point to calculate the optimum exposure.


Partial metering is more effective for strongly backlit subjects, metering is weighted at the center of the frame covering 8.5% of the viewfinder area.

Spot metering is useful for metering very precisely a single subject or area within a scene. The metering is weighted at the center of the frame covering 2.4% of the viewfinder area. With AF points limited to 11 or 9 (custom function 13 is 1 or 3) the metered spot will follow the AF point.
Center-weighted Average

In this mode the entire frame is metered but more emphasis (weight) is placed on the center portion of the frame.

  • C.Fn I-10 allows you to disable any of the metering modes.

Drive modes

The EOS-1Ds Mark III can shoot 21 megapixel images at a rate of 5.0 frames per second and buffer up to 18 Raw files or almost unlimited JPEG files. At full tilt (at five frames per second) the Mark III is processing an mighty impressive 185 MB of data every second.

Mode Description
S Single frame Silent Shooting

The shutter and mirror noise are reduced in Silent Shooting mode.

Single frame

A single shot is taken for a full press of the shutter release.

Continuous *1

Press and hold the shutter release and the camera shoots until the buffer is full. As soon as there is space in the buffer (images have been written out to the CF card) the next shot will be taken. There are two continuous modes (Cont-H and Cont-L).
Self-timer 10-sec delay

Camera pauses 10 seconds before taking shot. Countdown is displayed on the top LCD.
Self-timer 2-sec delay

Camera pauses 2 seconds before taking shot. Countdown is displayed on the top LCD.

*1 C.Fn III-16 allows you to reprogram continuous modes to 4, 3, 2 or 1 fps.
  C.Fn III-17 allows you to limit the number of shots in continuous mode, when this setting is enabled the camera will only shoot the specified number of frames for any single press-and-hold of the shutter release button.

Top of camera controls (right)

The main change to the right side of the camera is the new dedicated ISO button, otherwise it's pretty much business as normal here.

Right side of camera controls

Button / combination
Acquires a flash exposure lock, attached flash will pre-flash and meter for the correct flash output.
Also used in Multi-spot metering mode to select a meter point.
Illuminates top or rear LCD status panels with blue LEDs for six seconds.
Select exposure compensation:

    • +/-3 EV in 1/3, 1/2 or 1.0 EV steps *1
ISO sensitivity *

 • L (50) (enabled via C.Fn I-3)
 • 100
 • 200
 • 400
 • 800
 • 1600
 • H (3200) (enabled via C.Fn I-3)
AE / FE Lock

Press to trigger automatic exposure and lock the exposure for the next shot. Hold the button to lock the exposure for more than one shot.
AF point selection button

Press to choose a single AF point, turn the main dial or the quick control dial to scroll around the available AF points. Alternatively you can also use the new multi-controller to select a point directly (press the selector for the center point). The exact function of this button can be programmed via C.Fn III-3.

*1 • Exposure compensation steps can be set to 1/3 or 1/2 EV via C.Fn I-1.
  • C.Fn IV-3 allows you to switch the functions of the AF point selection, Exposure Compensation and ISO buttons when you reassign the Quick Control dial when the metering is active.
  • C.Fn IV-1 allows you reprogram the function of the shutter release and AF