IV. DISCUSSION OFNEW AND IMPROVED FEATURES 17
Metering and
Exposure Control
Custom Functions
Having the same drive mechanism asthe EOS-1D Mark III, the EOS-1Ds Mark III’smaxi-
mum continuousshooting speed is 5 fps in both the One-Shot AF and AI SERVO AF
modes. Thisrate is achieved with 8-channel reading, DDR-SDRAM (twice the capacityof
the EOS-1DsMark II’s), and Dual “DIGIC III” Image Processors. Continuous shooting
speed can also be adjusted with C.Fn III-16 [Continuousshooting speed] as follows:
High-speed continuouswithin 2 to 5 fps, and low-speed continuous within 1 to 4 fps.
The metering opticshave the metering lens and 63-zone metering
sensor positioned atthe rear of the pentaprism. The 19 AF points in
the Area AFoptimally match the metering sensor’s zones.
The same 4 metering modesas in the EOS-1D Mark III are provided.
Partialmetering covers about 8.5% of the viewfinder area at the
center, and spotmetering about 2.4% at the center.
Because the metering area within the viewfinder issmaller than that of the EOS-1D MarkIII,
the algorithm hasbeen optimized for the EOS-1Ds Mark III. However, the basic algorithm
isthe same as the EOS-1D Mark III’s.
ISO bracketing isnot provided in either the EOS-1Ds Mark III or the EOS-1D MarkIII.
With the Ec-A, Ec-B, Ec-I, and Ec-Linterchangeable focusing screens, only spot metering
outside the center and center-weighted average metering ispossible. Since the prism
centersof these focusing screens are plainly transparent, an error will occur with evalua-
tive metering, partial, and center spotmetering.
The Custom Functionsare the same as the EOS-1D Mark III’s. The Custom Function
names, settings, numbersand so forth are the same. The only exceptions are C.Fn I-3
[SetISO speed range], C.Fn I-8-2 [Safety shift: Enable (ISO speed)], C.Fn I-15-1 [Flash
sync. speed in Avmode: 1/250 sec.], and C.Fn III-16 [Continuous shooting speed]. Either
the setting valuesor control values have been changed to suit the EOS-1Ds MarkIII’s
specifications.
*C.Fn I -7-1 enables AF point-linked spot metering.
Evaluative/Center-weighted
average metering Partial metering Spot metering
Metering Sensor
Metering Zones