mmmm ... but this cannot really be done in LFS, if that's what you meant. So to achieve such an effect it would have to be faked in post production.
Or is that what you meant?
It's what I meant anyway, in my previous post. I've never done such a faked effect, but if there is a method to doing so, I'm interested in knowing how. Then i can see if it can be made easier, although i suspect all the required data is already there. If you'd have to fake it in After Effects, then you can already have depth information in there in the shape of camera and null layers at which the camera could focus, or by whatever means the effect is achieved. I guess it requires something like depth maps to indicate the amount of blur on each position on the screen .. just guessing here ..