The greater the distance, the more closely this projection resembles the Orthographic projection. All aspects are circular projections of an area less than a hemisphere. A single point located anywhere on the globe. The central meridian of the projection. The arial scale decreases with distance from the center.
Arial scale is zero at the edge of the hemisphere.
True direction from the point of tangency. The radial scale decreases with distance from the center and becomes zero on the edges. The scale perpendicular to the radii decreases, but not as rapidly. The actual range depends on the distance from the globe. In all cases, the range is less than 90 degrees from the center.