#7. The 1D IVs 63-zone metering unit is inherited directly from the 1D III
he metering sensor’s zone correlation has been optimized for the Area AF frame’s 45 AF points. Evaluative, Partial, Spot, and Center-weighted average metering are provided. Partial metering uses about 13.5% of the viewfinder area at the center. Spot metering uses about 3.8% of the viewfinder area at the center. The 1D IV’s Evaluative metering algorithm has been improved for less metering dependence on the subject and more consistent metering control.