UDMA (Ultra DirectMemory Access) is a new specification for CF cards (Compact Flash
Specification Revision 4.0) to enable high-speed writing to the card. With a UDMA-com-
pliantCF card, the data transfer speed is twice as fast as with the EOS-1D MarkIII, and
the writing speed ison par with the EOS-1D Mark III (and about 3 times as fast as the
EOS-1DsMark II) even though the pixel count is twice as large.
With a higher number ofpixels in the same sensor dimensions, the pixel size is neces-
sarilysmaller than those of the EOS-1Ds Mark II. Nevertheless, the ISO speed range is
the same asthat of the EOS-1Ds Mark II with ISO 100 to 1600 and ISO extensions of 50
(L) and 3200 (H).* The ISO speed SafetyShift is enabled via C.Fn I-8-2. The ISO speed
controlvalue differs from that of the EOS-1D Mark III. Note that the maximum burst dur-
ing continuousshooting will decrease if ISO speed safety shift, noise reduction for high
ISO speeds(C.Fn II -2-1), or a high ISO speed is set. (The maximum burst during contin-
uousshooting is displayed in the viewfinder.)
*Standard outputsensitivity. Recommended exposure index.
The EOS-1DsMark III uses the EOS Integrated Cleaning System, a complete dustreduc-
tion system for reducing dustadhering to the imaging sensor, removing dust, and mak-
ing dustspots less noticeable. The Self Cleaning Sensor Unit isa newly designed, dedi-
cated unitoptimized for the full-frame CMOS sensor. As with the EOS-1D Mark III, this
unithas two thin piezoelectric elements that apply ultrasonic vibration to shake dust off
the infrared absorption glasswhich is the outermost layer in front of the low-pass filter.
The removed dustthen sticks to the absorbent material lining the perimeter of the
infrared absorption glass. Mechanismssuch as the shutter and the mirror are manufac-
tured in waysthat reducethe generation of dust. The LPF uses grounding and a conduc-
tion processto discharge static electricity, minimizing dust adherence. And, to prevent
the dustfrom enteringthe internal parts, the unit’s outer periphery is sealed. The speci-
ficationsof the unit’s operating condition, forced termination condition, and Dust Delete
Dataacquisition and application are the same aswith the EOS-1D Mark III.
Aswith the EOS-1D Mark III, 6 drive modes (single shooting, high-speed continuous,
low-speed continuous, 10-sec. self-timer, 2-sec. self-timer, and silentsingle shooting)
are provided. The noise levelof the single shooting and silent single shooting modes is
the same aswith the EOS-1D Mark III.
IV. DISCUSSION OFNEW AND IMPROVED FEATURES 16
New UDMA Compatibility
ISO Speed
EOSIntegrated Cleaning
System
Drive
Piezoelectric element
Supportmaterial
Low-pass filter
CMOS sensor
Infrared-absorption
glass
Sealing material
SelfCleaning Sensor Unit Construction Diagram AbsorbentMaterial