If it's a GameCamera, then AC will not affect the zoom level so long as the Field Of View panel in its Inspector has Lock? checked.
When locked, the Camera's fieldOfView can be controlled with a separate script attached to it. This isn't related to AC, but you should be able to find plenty of examples on the Unity forums.
Once you have a script that has a function that does what you want, you can call that function in an AC ActionList by using either the Object: Call event or Object: Send message Action.
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What kind of Camera?
If it's a GameCamera, then AC will not affect the zoom level so long as the Field Of View panel in its Inspector has Lock? checked.
When locked, the Camera's fieldOfView can be controlled with a separate script attached to it. This isn't related to AC, but you should be able to find plenty of examples on the Unity forums.
Once you have a script that has a function that does what you want, you can call that function in an AC ActionList by using either the Object: Call event or Object: Send message Action.