Examples

Vesuvio

This is the basic example.

The reference plane is the sea, the camera is at eye sight (1600mm), no tilt.

Infinity is reached at horizon.

Halles

The plane has a slight constant slight slope.

While you move the plane, you see the lines intersection with the building to show exactly the points in the same plane. For the focus plane, you can choose any plane of this line.

The infinity corresponds to the line above the plane in its extremity. Just imagine a person with the same height and align at eyes level to find infinity.

Seine

Here h is (height) is not anymore 1600. I have estimated the height above the Seine to 4 times my height (=6400mm)