If the settings are changing, the camera is still metering. For example, if you set the metering timer to 10 seconds - the camera will meter for 10 seconds after you half-press the shutter. If you don't do anything after 10 seconds, it will stop metering. The reason the camera isn't always metering is because it helps to save battery.. The Metering Timer value affects: 1) how long the metering values are updated after pressing the shutter button half way down (or whatever button you have assigned to metering); for example, in Av mode the shutter time is updated for the amount of time set, after that metering will stop. 2) how long an exposure lock is held.
Metering Timer. You can set how long the metering timer runs (which determines the duration of exposure display/AE lock) after it is triggered by an action such as pressing the shutter button halfway. Select [: Metering timer]. Set a time option. Contents. EOS-1D X Mark III; About This Site.. Metering Timer. You can set how long the metering timer runs (which determines the duration of exposure value display/AE lock) after it is triggered by an action such as pressing the shutter button halfway. Select [: Metering timer]. Set a time option. Contents. EOS R5; About This Site.