I know this thread is old, but it is the only one I found which is perfectly matching my problem.
I got a composition with a 3D camera, lots of movement, small DOP.
If something is out of focus, it doesn’t look like a regular blur, its just all blocky.
I know something similar from 3D software, usually there is a simple controller to increase to get a higher quality blur. Is there something similar in AfterEffects CS5 or CC? The animation was too much work to redo it with another method..