Doesn't mean he didn't use something similar. David Hockney made this point in 2001 (if I recall). Besides, Brunelleschi used a mirror to demonstrate the effec

Doesn't mean he didn't use something similar. David Hockney made this point in 2001 (if I recall). Besides, Brunelleschi used a mirror to demonstrate the effectiveness of his perspective drawings in the 1400s: http://zeiteye.files.wordpress.com/2012/01/c1450_brunelleschi_mirror-perspective-tool.jpg?w=510 http://zeiteye.files.wordpress.com/2012/01/c1450_brunellesch... Durer used string and moveable panel in his perspective studies: https://www.dartmouth.edu/~matc/math5.geometry/unit11/durer.gif https://www.dartmouth.edu/~matc/math5.geometry/unit11/durer..... And of course, there was the camera obscura. I can't believe there wasn't any development in drawing aids in the 400 years since Bruneschelli's demonstration.