So I’m making a little depth of field test using a defocus filter, and I was wondering how I could make it so in the beginning of my anim the camera would focus on a cube that is close to the camera, and then slowly transition to a cube farther away from the camera.
How would I go about doing that? and what kind of keyframe would I use?
Easiest is to animate an empty and setting that as focus under the camera settings (select the empty object). 
Thank you