At first I was confused if the focus is on the girl,why there are circles of confusion on both objects closer to and far away from the camera. Then I realized the circle of confusion can be formed both before or after the plane.
since the rays have crossed before they hit the sensor to form the circle of confusion, does this mean that the light from the object that creates the circle of confusion is actually flipped in this case? so if the point light source has a top color and a bottom color, on the blurred part of the image where the object appears will those two colors be flipped?
I just want to confirm since I'm a little confused by the notation -- z'_s here is referring to the focus distance, not z_s right?