Like this?
Can also be handy as a helper utility, tho not much in the case of physical (photo-based) approach. ;)
Considering Corona's physical camera properties be aware that DOF blurs up to
infinity.
It's not the same as the fake DOF (post fx) with cinema's AR, where you can set max & min for both (front & rear) independently.
Tho you can always generate the depth pass and use that in post for more artistic control.
BTW
DOF intensity depends on:
a) Lenses:- Focal Length > Smaller Focal Length = Stronger DOF
- F-stop > Wider Aperture Diameter = Stronger DOF
b) Film Format (analog) / Sensor Width (digital) > Larger the Film or Sensor size = Stronger DOF
Until IPR comes to play... enjoy Experiencing & Learning photography :D