All meters read 18% gray or zone V, a wide angle reflective meter or an incident meter reads middle gray, assuming that the scene has a normal range of values. A spot meter reads 3% to 1% of the scene and assumes that the photographer will find a middle gray or render the most important element middle gray. If Helen had taken a reading of a gray card on the pavement the pavement would have fallen in zone II to IV. The zone system was designed to let the photographer chose how the most important aspects of the scene will be rendered (previsualization), The church in Toas New Mexico that Ansal Adams took many pictures of is not snowey white, at least the last time I was there in the 70's, it is an off white. The photographer meters for the shadows allowing the shadow to render detail and develops for the high values. Sound easy but it is not, takes a lot of work.

Being lazy and having developed many bad habits of the years I just bracket, some times 3 to 4 stops over and under and fix in the dark room.

Still confused in Phoenix