When the images of one sharply focussed object and one blurred object abut:

Question

Quizplus · Accepted Answer

If the border between the sharply focused object and the blurred object is sharp, it indicates that the blurred object is more distant. This is because a sharp border suggests that the blurring is not due to the transition between the two objects but rather due to the object itself being out of the depth of field, implying it is further away from the plane of focus.

When the Images of One Sharply Focussed Object and One