Canon MARK IV User Manual (en)

 Selecting the Metering Mode
With multiple spot meter readings, you can see the relative exposure 
levels of multiple areas in the picture and set the exposure to obtain the 
desired result.
Set the metering mode to r spot metering.
Press the <I> button. 
Aim the spot metering circle over the area where you want a 
relative exposure reading, then press the <I> button.
On the right of the viewfinder, the relative exposure level will be 
displayed for the spot meter reading taken. For the exposure, the 
average of the spot meter readings will be set.
While referring to the exposure level indicator’s three spot metering 
marks, you can set the exposure compensation to set the final 
exposure and obtain the desired result.
Multi-Spot Metering
You can take up to eight spot meter readings for one picture.
The exposure setting obtained with multi-spot meter readings will be 
canceled in the following cases: 
• After taking the last spot meter reading, 16 seconds elapsed.
• You pressed the <W>, <o>, <Q>, <Z>, <S>, or
<O> button.
• After taking the picture, when metering timer expires.
When [8C.Fn I -7: Spot meter. link to AF point] is set to [1: Enable 
(use active AF point)
] (p.210), multi-spot metering is still possible.