Viewfinder / Autofocus
Below you can see a proportional comparison in the difference in field of view when looking through the EOS-1D viewfinder (1.3x field of view crop) and the EOS-1Ds viewfinder (no field of view crop). As you can see the full-frame sensor means that viewfinder view is considerably larger and brighter.
The diagrams show the AF ellipse and 45 focus points, the center spot as well as meter indicators (active points will glow red once AF is locked), buffer space indicator (88 JPEG) and camera status readout (horizontally along the bottom). Unlike the EOS-1D the EOS-1Ds always indicates 10 frames available in the buffer (before shooting) no matter what the ISO sensitivity.
|EOS-1D viewfinder view (1.3x FOV crop)||EOS-1Ds viewfinder view (no FOV crop, big!)|
In automatic AF point selection mode the camera will highlight (glowing red) the AF points which were used to measure AF distance. On the right side of the viewfinder is the eyepiece shutter lever (not visible above), this allows you to blackout the viewfinder eyepiece to prevent stray light entering the camera during long or remotely triggered exposures.
|Auto Focus sensor (CMOS)||Cross-type sensors (horizontal and vertical sensitive) only with lenses with max. aperture of F2.8 or faster|
The EOS-1Ds uses the same 45-point area AF CMOS sensor used in the EOS-1D/1V, it measures 15 x 8 mm and is located just below the semitransparent mirror and receives the exact same image you see through the viewfinder.
All AF points are sensitive to horizontal detail, however for a lens with a maximum aperture of F2.8 or faster lens a vertical row of 7 points (as indicated in red in the diagram above, right) become sensitive to both horizontal and vertical detail, and the manual notes, are three times more sensitive than the normal horizontal sensors. Some other L lenses with maximum apertures of F4 or brighter make use of the center cross-type AF point.
Having 45 focusing points isn't just about being able to choose your focus area within the image it also means that focus tracking (AI Servo) can be much more effective (as the subject is more likely to be picked up by at least one AF point).
AF point selection modes
|Automatic selection - in this mode
the camera will automatically select (and indicates) the AF point(s)
which have been used to calculate the focus distance.
C.Fn 10 allows you to change or disable the method of focus point indication.
|45 AF Point Manual selection - in this mode the main dial (top of camera) moves the AF point horizontally, sub command dial (rear) moves AF point vertically.|
|11 AF Point Manual selection - in this
mode the main dial (top of camera) moves the AF point horizontally,
sub command dial (rear) moves AF point vertically.
C.Fn 13 - 1 or 2
|9 AF Point Manual selection - same
procedure as described in the other modes, the AF Assist button and
sub command dial can be used to quickly select a peripheral point.
C.Fn 13 - 3
Registered AF point
The EOS-1Ds has also has a 'registered AF point' feature, this allows
you to store the position of a most used AF point (such as the center
point) and have it activate when the AF Assist and AF Point buttons are
pressed, this is extremely useful for quickly switching back to a default
| P.Fn 23 allows you to change the 'meter on' time (default 6 seconds).|
| C.Fn 11 can be used to change the controls used to select focus points. C.Fn 17 allows you to activate the six AF points surrounding the selected AF point (7 total) or allow the camera to select a maximum of 13 AF points including selected AF point.|
| C.Fn 18 can be used to change the buttons used to switch to the registered AF point.|
Diagrams reproduced from the EOS-1Ds manual by permission.
Metering system / zones
Just like the EOS-1D/1V the 1Ds has a 21-zone evaluative metering system. This provides several metering modes: evaluative, partial, spot, center-weighted average, AF point-linked spot and Multi-spot metering (plus flash E-TTL and TTL). The diagram on the left, above shows how these areas equate to the portions of the viewfinder view and AF points, in AF point-linked spot metering mode one meter zone serves several AF points.
|21 metering zones over the viewfinder view image||21 zone meter sensor|
| C.Fn 13 allows you to choose the number of AF points as well as whether spot metering follows the AF point or stays in the center of the frame.|
Lens mount / Mirror / Shutter
The mirror mechanism is the same as found on the EOS-1D/V, that means
it also features the same Active Mirror Control system which uses a 'shock
absorber' to soak up the bounce produced when the mirror flips back down
to the normal position. This system means that 'mirror blackout' (the
amount of time the viewfinder view is black) is just 87 ms.
| C.Fn 12 enables 'Mirror lockup' mode, in this mode the first press of the shutter release locks the mirror up, the second press opens and closes the shutter curtain (and thus takes the shot). This mode is especially useful for shooting long exposures or high magnification macros.|
| P.Fn 21 allows you to enable 'Quiet, delayed shutter cocking' (great name). When this is enabled the mirror is lifted while the shutter release button is fully depressed and released more slowly (and quietly) once the button is released.|
White balance sensor
Just like the EOS-1D and previous the EOS-D2000 (but unlike the D30/D60 or other recent digital SLR's) the EOS-1Ds has an external white balance sensor mounted on the top right corner of the camera (from the front). This is used to provide 'additional information' to the camera's white balance system in combination with any reading measured by the main sensor. Canon have coined the name 'hybrid automatic white balance system'.