No "Point and Shoot"
The most common method used in capturing the repeat shot correctly is a process of matching closest foreground features with distant background features and choosing to focus on several key elements (rocks, trees, rooftops) until a match to the original is found. At this point there occurs only a momentary "Eureka!" Add some GPS coordinates and Google Earth to the mix, and then the crucial next step involves choosing the appropriate lens for the repeat photograph. The goal is to match the optical equation of the original photographer so that the modern-day camera can duplicate the original as closely as possible. When the two photos being taken are separated by one hundred years, the difference in camera technology between the two eras becomes a large issue—just one of numerous challenges the repeat photographer faces. On average it can take the repeat photographer an hour to set up the shot. The variables of chance create an atmosphere where there are no hard and fast rules regarding how exactly to make a repeat photograph. There are always limitations; it may be unclear what time of year and time of day the original photograph was made, which affects the lighting and shadows, which can greatly alter the outcome. Some of these challenges are lesser factors in Northern Arizona; regardless, the practice of repeat photography takes a combination of artistic and scientific intelligence that is not simple or straightforward.