Depth of field does not affect reflections!

Although it may seem counter-intuitive, this is not a bug, and this phenomenon is something that happens in real life.


Examples


Example renders - the fireplace reflection remains sharp even though strong DoF is observed on the wall.







Real-life examples


To verify this, you can refer to these simple experiments:

Reflection:
  • Close one eye, then take a mirror and place it very close to your open eye - despite the fact that the mirror is very close to your eye, you can still see sharp reflections of the far away objects
  • Imagine that you are looking through an SLR viewfinder - your eye is very close to a tiny mirror, yet you are able to see everything clear
  • Look at a flat mirror hanging on a wall - you will observe that it behaves like a hole, or like a window - you see flipped version of reality in it
This phenomenon applies to flat reflections only. This will not happen for reflections seen on curvy objects like water drops, or Christmas baubles.

Refraction:
  • Wearing glasses or contact lenses - the image viewed through them will appear sharp, although the refractive objects are extremely close to the wearer's eyes
  • Using cameras (also scopes, binoculars, etc) would be impossible if what is seen through the lens would get blurred
  • Photos of water drops in macro scale, where the refracted image is sharp

It is impossible to recreate these effects when adding DoF in postproduction using the Z-depth pass.


Related forum topics:
Problem with refraction's and Camera Depth Blur in Corona