the vertical plan on which you work out the perspective of the objects seen is of the same form as the wall on which the work is to be executed.
546.
OF PAINTING.
The size of the figures represented ought to show you the distance they are seen from. If you see a figure as large as nature you know it appears to be close to the eye.
547.
WHERE A SPECTATOR SHOULD STAND TO LOOK AT A PICTURE.
Supposing a b to be the picture and d to be the light, I say that if you place yourself between c and e you will not understand the picture well and particularly if it is done in oils, or still more if it is varnished, because it will be lustrous and somewhat of the nature of a mirror. And for this reason the nearer you go towards the point c, the less you will