Blur out a backgroung

[Eric Jurgenson]

I assume you have a foreground subject. In After Effects, you could create an animated mask around the foreground object (cutting it out), and layering it over the blurred background (or you could just darken the background, etc). It’s doable, but pretty hard if you aren’t familiar with the program. But, hey, learn by doing, right?

A good place to start would be the instruction manual section about creating a freeform mask for a layer (after you figure out how to set up a project/composition); then learning about how you can modify each keypoint as the subject moves by animating them. It’s pretty easy once you figure out the program.