Orthogonals

Battle of San Romano, 1430's. Panel 6' x 10' 7". National Gallery, London. By Paolo Uccello.

Christ Giving the Keys to St. Peter, 1481 Fresco. 11' 5 1/2" x 18' 8 1/2 ". Sistine Chapel, Vatican, Rome- by Perugino

"d" points out the orthogonals.

Orthogonals: Lines running at right angles to the plane of the picture surface but, in a representation using one-point perspective, converging toward a common vanishing point in the distance. (Hart)

The lines on the ground in the middle ground of Perugino's fresco are a nice example of orthogonals.

Paolo Uccello loved the use of orthogonals, some say he 'overdid' his use of them in most of his paintings - The Battle of San Romano is a nice example - especially in the foreground.