Lanci's most notable achievement was his invention in 1567 of a piece of surveying equipment to obtain perspectives with a visual field of 180°. The instrument, which he named "distanziometro" ("distance meter"), was made of a circular bronze plate placed upon a horizontal tripod the height of which could be adjusted. Semi-cylindrical paper was wound around its edge. A cylindrical eyepiece was placed in the centre with a retracting metal needle or pen underneath. The eyepiece was high enough to overlook the semicircle of paper and sight points of interest while the retracting needle scored on the paper to accurately plot the subject. It could also be used as a quadrant for measuring height in much the same way as the orizzonte designed by Leon Battista Alberti.