I wanted to know this also. My Apple MacBook. Select Camera view, and camera object.

Make sure the View Lock "Camera to View" button is OFF! (this is what got me)

Hover over the "frame". On the trackpad, it is 'control' or 'command' and a 'two finger' vertical swipe.

I wanted to know this also. My Apple MacBook. Select Camera view, and camera object.

Make sure the View Lock "Camera to View" button is OFF! When set to ON it the following only alters the zoom (this is what got me).

Hover over the "frame". On the trackpad, it is 'control' or 'command' and a 'two finger' vertical swipe alters the size.