[brokenmachine]

The lenses would still have a limited depth of field though, like a photo from an SLR.

Wouldn't that make the background be blurred? Or is that kind of blur somehow different to motion blur?

[cma]

Motion blur indicates direction, you could maybe use a weird aperture shape to simulate it, but things at different depths wouldn't blur right due to not picking up different parallax movements the same way, and other moving objects that weren't in focus wouldn't have their motion blur picked up correctly.

[brokenmachine]

Oh yeah, that makes sense.