Apparently, the use of two picture planes to draw a single view has not been attempted before. Most perspective methods, after Alberti, take for granted the use of a single picture plane, disregarding its likely use in dual positions. What if two picture planes are necessary to draw a single view—for example, given a lack of spatial references at ground level to estimate the distance between two objects? This article demonstrates that to draw the interior of a building from which another building can be seen about 190 m away, where the projection of such building on the first picture plane would be imprecise, it may be wise to use a second picture plane. This leads to consideration of how objects change shape as they move away from the viewer. For example, if a cube recedes from the observer up to 100 times its side length, it takes on an axonometric view. This raises a question: Could axonometric projection be a particular case of perspective?

ABSTRACT The accurate perception of a painting's image formation depends upon three concepts: the observer's distance to the perspective plane , the aperture of his or her visual field, and the limits of the perspective plane. A comprehension of these concepts is crucial to the calculation of both the painting's image formation and the observer's vantage point. To approach this problem in Leonardo da Vinci's Last Supper , the author introduces the reverse outlining perspective method, through which it is shown how the painting's image formation can be deduced.