TY - JOUR T1 - The uncatchable smile in Leonardo da Vinci's La Bella Principessa portrait. AU - Soranzo,Alessandro, AU - Newberry,Michelle, Y1 - 2015/06/04/ PY - 2014/11/21/received PY - 2015/05/20/revised PY - 2015/05/22/accepted PY - 2015/6/7/entrez PY - 2015/6/7/pubmed PY - 2016/4/19/medline KW - Facial expression KW - La Bella Principessa KW - Leonardo da Vinci KW - Mona Lisa KW - Portrait KW - Visual illusion SP - 78 EP - 86 JF - Vision research JO - Vision Res VL - 113 IS - Pt A N2 - A portrait of uncertain origin recently came to light which, after extensive research and examination, was shown to be that rarest of things: a newly discovered Leonardo da Vinci painting entitled La Bella Principessa. This research presents a new illusion which is similar to that identified in the Mona Lisa; La Bella Principessa's mouth appears to change slant depending on both the Viewing Distance and the Level of Blur applied to a digital version of the portrait. Through a series of psychophysics experiments, it was found that a perceived change in the slant of the La Bella Principessa's mouth influences her expression of contentment thus generating an illusion that we have coined the "uncatchable smile". The elusive quality of the Mona Lisa's smile has been previously reported (Science, 290 (2000) 1299) and so the existence of a similar illusion in a portrait painted prior to the Mona Lisa becomes more interesting. The question remains whether Leonardo da Vinci intended this illusion. In any case, it can be argued that the ambiguity created adds to the portrait's allure. SN - 1878-5646 UR - https://www.unboundmedicine.com/medline/citation/26049039/The_uncatchable_smile_in_Leonardo_da_Vinci's_La_Bella_Principessa_portrait_ DB - PRIME DP - Unbound Medicine ER -