5. New Autofocus System

The EOS-1Ds Mark III uses the same autofocus system introduced earlier this year on the EOS-1D Mark III DSLR. It has 45 autofocus (AF) points including 19 higher precision cross-type points and 26 Assist AF points. This array allows the 19 cross-type points to be divided into groups of nine inner and nine outer focusing points plus a center point, making picking an individual focusing point faster and easier than going through all 45. During manual AF point selection, the AF point area is expandable in two stages via Custom Function control.

The new focusing system also allows for very fine adjustment of the AF point of focus depending on the type of lens being used. Focus tracking sensitivity is also now adjustable and the low light sensitivity of the AF sensor has been doubled to EV-1 allowing better focus in dark environments.

EOS Integrated Cleaning System

The 1Ds Mark III uses Canon’s dust management system called the "EOS Integrated Cleaning System". The CMOS image sensor has a lightweight infrared absorption glass cover that vibrates for 3.5 seconds when the camera is turned on or off. Dust that is shaken or blown loose of the sensor is trapped by adhesive surfaces surrounding the sensor unit housing.

The 1Ds Mark III’s self cleaning sensor

Like the EOS-1D Mark III, the shutter of the EOS-1Ds Mark III has durability rating of 300,000 cycles. It charges itself three times during the manual cleaning process shaking dust from the shutter curtains as well. The cleaning system is said to uses very little battery power and can be turned off in the custom function menu.

The camera’s shutter unit

The dust management system also includes software that maps the location of spots that may remain on the sensor. This information is saved and attached to the image file. The Digital Photo Professional software included with the camera can be used to remove dust from the image.

Post processing software removes dust from images.