Exposure settings: 100,000-pixel RGB AE sensor
Introduced with the EOS-1D X, the 100,000-pixel RGB sensor is able to measure not only light levels, but also to detect colour information and the presence of a face within the frame.
During metering, the sensor divides the frame into 252 zones, compared to 63 metering zones used in the EOS-1D Mark IV. The 252 metering zones are also used for flash metering allowing for more precise subject location based on pre-flash readings.
In low ambient light conditions, where some zones may receive little or no light and therefore could lead to inconsistent exposure, the sensor enlarges each zone so that it meters from 35 zones.
Because the metering sensor captures RGB data, it is able to calculate the colour of the scene. This is how it is able to provide colour-tracking information to the AF system and face detection data, both for AF and Auto Scene detection. The sensor is especially aware of green and yellow as these colours can adversely affect the exposure reading and cause over-exposure or under-exposure respectively. By using the colour data and information from the 61 AF points, the EOS-1D X is able to detect where in the frame the subject is and then bias the exposure accordingly to ensure the best exposure setting. This provides more stable and accurate exposures than those possible with the EOS-1D Mark IV.
The colour and face detection system is also used in the E-TTL II flash metering algorithm. By locating a face within the frame, the EOS-1D X can accurately adjust the flash output to ensure the face is correctly exposed, while ignoring reflective objects within the frame that may otherwise lead to an inaccurate flash exposure. Beyond this addition, the E-TTL II algorithm functions in the same way as it does on the EOS-1D Mark IV and other models within the EOS DSLR range.