14 May 2014

Leonardo’s Secret Perspective

Compiled from Leonardo’s manuscript pages, the Codex Atlanticus contains two strange sketches, two oddly elongated figures. They are both sepia drawings. They are also baffling to the eye at first glance, but if you look at them from a flat oblique angle from the right rather than from straight on as normal, they reveal both an infant’s head and an eye. Art historians call this type of image anamorphosis, and commonly cite Leonardo’s Eye and Head of an Infant as the very first examples of anamorphic representation that we know of. The Codex Atlanticus is kept in the collection Biblioteca Ambrosiana in Milan, which is probably where the drawings themselves were made. At the time, the city was mostly under French rule, and its French governors, Charles d’Amboise and Gian Giacomo Trivulzio, became Leonardo’s chief patrons after he was invited to Milan by Lodovico Sforza. Between 1515 and 1521, the office of vice governor was held by Jean de Selve, father of Georges de Selve, the man on the right portrayed in Hans Holbein’s The Ambassadors, perhaps the most well-known anamorphic painting in art history. The future bishop, who lived in Milan from the age of six to twelve, was not fortunate enough to have known Leonardo in his lifetime, but he undoubtedly would have heard a great deal about the revered artist, not least as the designer of the ornate court ceremonies where the theatrical effects were heightened by perspectivist, indeed probably anamorphic, visual elements. Leonardo lived in Milan between 1482 and 1499 working as the court scientist and artist of Lodovico Sforza. In 1499, he was forced to leave the city in the wake of the French occupation. In 1506, it was the French who invited him back. Ironically, when his French patrons relinquished Milan to the Sforzas who reclaimed power, Leonardo was forced to flee from his former employers. When Francis I retook Milan in 1515 and appointed the father of Georges de Selve governor, Leonardo had long vanished, and, as far as we know, never returned. If the young Georges de Selve had a chance to see Leonardo in the flesh at all, that could have been in Bologna in December 1515. At least it is interesting to imagine him being around, in the company of his father, when the negotiations between Francis I and Pope Leo X took place which resulted in the Concordat of Bologna, and witnessing the famous ceremony that Leonardo designed for the occasion. The little boy must have marvelled at the scene for which Leonardo constructed a mechanical lion, the emblem of the Medici Pope, which walked forward, tore open its chest and strewed Bourbon lilies at the astonished audience. Incidentally, the agreement signed in Bologna would have momentous consequences for Georges de Selve, even if he did not know it at the time: it conferred upon Francis I the right to appoint his Episcopal bench, and he would make Georges one of his bishops by way of rewarding the services rendered by his father. The Ambassadors captures the moment when the young man puts on the Episcopal mantle officially for the first time. (Although his appointment had been decided in 1526, it was not until 1533 that he was consecrated, at the age of 25.)

Jean de Selve and Jean de Dinteville, the other ambassador in Holbein’s painting, obviously had the opportunity later in France to see Leonardo manuscripts in the original or at least in copies, since his works must have circulated widely in those days. This much can be inferred from the memoirs of Benvenuto Cellini, who in 1542, while at the court of Francis I, bought from an impoverished nobleman at a knock-down price Leonardo manuscript copies that included essays on the three major art forms (sculpture, painting, architecture) as well as on perspective. “It was the most beautiful thing ever conceived by man,” writes Cellini, “revealing the various ways in which objects are foreshortened in depth, width and height. Leonardo had elaborated the rules of foreshortening, and explained them in words so simple that everybody who laid eyes on such a work could immediately understand it.” Had Leonardo merely written about the rules of conventional perspective, Cellini would hardly have been moved to these superlatives, given that those rules had been discussed so many times since Alberti that any apprentice painter worth his salt knew them by heart, no matter which bottega he hailed from. It is much more likely that what Cellini was trying to describe – or, rather, circumscribe – by noting the distortion of objects in depth, width and height,was simply the technique of anamorphosis, for which no word existed at the time; the term of Greek origin, meaning “re-formation” or “back-formation” was introduced much later, by the Jesuit scholar Gaspar Schott, in his 1657 work Magia Universalis. In those days, magia anamorphotica was a special field of science rather than an artistic genre. Diderot’s 1751 Encyclopaedia offers the following definition under the “Anamorphosis” entry: “The term anamorphosis denotes unrealistic or distorted images that nevertheless appear natural, with correct dimensions, when viewed from a specific angle.” In Leonardo’s day, all phenomena related to the rendering of space in two dimensions went by the name of prospettiva. Unfortunately, the manuscript mentioned by Cellini did not survive, but we do know a few drawings by Leonardo, including some fascinating and very vividly executed shadow distortions, to which the illustrations Cellini talks about must have been similar. Some of these drawings are kept in the collection of the Institut de France in Paris. Also extant are a few accounts proving that Leonardo produced not only anamorphic sketches but fully developed anamorphic paintings as well. One of these accounts is by Leonardo’s student, partner and heir, who mentions a painting depicting the fight between a dragon and a lion – reconstituted for those who turned the tablet sideways to view it from an oblique angle. Melzi also recalls another work from Leonardo’s later period revealing horses from a similar perspective; this was later reportedly acquired by King Francis I. Another Leonardo disciple worth mentioning in connection with anamorphosis was Gaudenzio Ferrari. Gian Paolo Lomazzo, in his 1584 Trattato, describes a Ferrari painting from the turn of the 15th and 16th centuries which, when viewed close up against the plane of the painted surface from a slanting vantage point through a peep hole, showed a wonderful profile of Christ. “Seen from the front,” writes Lomazzo, “Christ’s hair resembled the waves of the sea.” From this description we can surmise a seascape painting quite unlike the amorphous jumble that most anamorphic representations appear to be when viewed from the front. Arguably, this “intelligible” sight acquired a different meaning by transmuting into a portrait of the Saviour through a shift in perspective. Not that this is a difficult conjecture to hold. Ferrari’s painting, like those Leonardo works discussed by Melzi, has long been lost to us, making it impossible to refute the hypothesis that these paintings offered a double meaning: one from the oblique angle of vision, and another from the conventional, frontal perspective. It is to be noted that Lomazzo’s treatise (Trattato dell’arte della pittura, scoltura et architettura, Milan, 1584) contains the first known appreciation of Giuseppe Arcimboldo, another artist whose work is founded on twofold meaning. True enough, Arcimboldo’s paintings did not haveto be viewed from a different angle to reveal a second meaning, but from a greater distance, taking a few steps back, or with narrowed eyes – a trick we might call pseudo anamorphosis.

Representation of the kind where the image must be viewed from an oblique angle, known as perspectival anamorphosis, is what Leonardo himself refers to when he says that “the perspective will appear flawed unless the spectator has his eye precisely at the level and direction where the eye was placed in doing this perspective. You should therefore make a window the size of your face or, better yet, a hole through which to view the object. If you do that, your work will undoubtedly look like nature”.(Codex Atlanticus, folio 249.) Anamorphoses like this would indeed be put on display by fitting to the frame a tablet with a peep hole drilled in it or by cutting a slot in the frame at the right place. It is reasonable to assume that the original frame of The Ambassadors had such a slot in it.

Incidentally, King Francis I, who came into possession of that certain horse painting, served as the subject of another anamorphic portrait, one found nearly a century and a half later in La Perspective curieuse, a book by the Minim friar Jean-François Niceron. Published in 1638, this work must be regarded as the first serious treatment of anamorphosis in print. Tabula scalata was the name given to a special kind of stepped picture which presents to the frontal perspective nothing but a set of strips pasted together in a harmonica-like pleat, but reveals its representational object when viewed from another angle and/or by using a correctly placed mirror. In our case, what then becomes visible is a portrait of the French king, along with an inscription identifying the subject being reflected in the mirror. But what was Francis doing in the mirror? How did he become part of a book printed in 1638, in which all the other portraits drawn by Father Niceron were of his contemporaries, and most of them of Louis XIII, who ruled at the time? There is little doubt that the image in question was a reproduction of an anamorphic portrait of Francis dating from his own reign, and from the early 16th century at that, for it shows a rather young king. And who could be more likely to have devised such an anamorphic portrait than the personal protégé of the king, the researcher of optics and perspective, the engineer of ingenious contrivances – Leonardo da Vinci? Indeed, it is quite possible that the vain monarch cajoled his ageing friend into preserving his image for eternity, and a Leonardo weary of painting must certainly have been more amenable to preferring a playful, tricky portrait to yet another oil on canvas. Leonardo’s anamorphic tabula scalata rendition of Francis I may have survived into the early 1600s, long enough to be seen, tested in operation, and copied by Father Niceron.

We could at this point move forward were it not for that hint about a certain nobleman fallen upon hard times from whom Cellini purchased the Leonardo folios. Always ready to brag about a good bargain, Cellini recounts having paid fifteen gold scudos for the manuscript. (Certainly not an extortionate amount for a man whose annual remuneration as the king’s silversmith was seven hundred scudos!) But more interesting to us than the mere sum is the identity of the povero gentiluomo, as Cellini described him, who put up his Leonardo manuscripts for sale. This happened only nine years after 1533, the date when Holbein completed The Ambassadors, to this day the best known anamorphotic painting. The man who commissioned the work was Jean de Dinteville, a diplomat appointed to the court of Henry VIII and pictured on the left, obviously commanding more attention than the other figure on the right. As a humanist patron of the arts, Dinteville must have had a hand in elaborating the intricate symbolism of the painting, and was probably responsible for persuading the German master to hide therein the anamorphic image of an unrecognisably distorted skull, which can only be identified when the viewer has hit upon a special oblique perspective. As Holbein had not painted anything like this before or after The Ambassadors, it seems safe to assume that it was the client who insisted on incorporating the anamorphosis and even showed his painter examples to follow –perhaps the very Leonardo drawings that would later be acquired by Cellini. In 1533, Dinteville must have made a comfortable, possibly luxurious, living if he was able to afford to retain Holbein’s services for The Ambassadors. Yet Cellini unmistakably describes the man he dealt with as being in need. In the second half of the 1530s the Dinteville family found themselves in the grips of a profound moral and financial crisis. A reclusive man prone to depression, Dinteville saw one of his brothers charged with sodomy, another accused of having poisoned a crown prince, and a third stripped of his Episcopal office and forced into emigration. In short, Cellini would have had reason to apply adjectives other than just “impoverished” to the purveyor of his bargain, for the man was probably none other than Jean de Dinteville himself, driven by a sudden shortage of funds to sell the priceless folios for a pittance. The two would have had ample opportunity to meet, since Jean de Dinteville had remained in the French king’s court as the man in charge of educating the young princes. The direct liaison between him and Cellini may have been Francesco Primaticcio, an artist often referred to as “Bologna” after his home town, who had kept friendly ties with Cellini, although in France the latter had come to regard him as more of a rival; at least this is how he speaks of his former friend in his autobiography. Primaticcio was friendly with the Dinteville family and had worked in Jean de Dinteville’s mansion in Polisy, where The Ambassadors hung on the wall, even painting a full-figure portrait of his host (Jean de Dinteville as St George before the slain dragon, 1544).

Hence, suffice it to say that, if Jean de Dinteville had indeed owned the Leonardo manuscript, Holbein must have seen the drawings in it. One cannot go as far however as to surmise that those anamorphic drawings included a distorted image of a skull, let alone that the underlying concept of The Ambassadors had even more than that to do with Leonardo.

The tabula scalata using mirror slates to conjure up a portrait of Francis I may be seen as a transition to another type of anamorphic representation, known as the catoptric. We know that Leonardo did study images seen in a curved mirror surface. Most of his experiments in this genre that are known to us employ concave curved mirrors. Using a swivelling pole-like measuring device, he was even able to determine the precise location where an object occupying a given point will become visible on the concave mirror column surface, and it is unlikely that he did not venture even further. Although none of his catoptric anamorphoses survive, the relevant sketches deploy a full arsenal of anamorphic techniques. This, combined with his invention of the camera obscura and the telescope – both representing even more complex forays into the territory of optics – make it quite conceivable that he did not stop at envisioning such devices but went on to build some of his own. Indeed, it was probably for the manufacture of special mirror objects for purposes of catoptric anamorphic imaging that, having moved to Rome in 1513, he employed a mirror maker and a metal forger named Giovanni Tedesco and, respectively, Giuliano Tedesco, their surnames indicating that the two artisans were German: Hans and Georg. Leonardo’s behaviour began to change at thattime, a sign he was mulling over some exciting ideas. Furtive about his work at the best of times, Leonardo now began to hide his notes and sketches, and stopped making new ones, apparently in the belief that his recently hired assistants were spies bent on stealing his ideas and smuggling them back to Germany. A letter to Giuliano Medici complaining about the German helpers survives in no fewer than six draft copies. We have no way of knowing to what extent Leonardo’s apprehension was founded. It is possible that the ageing master had succumbed to sheer paranoia, although it is a fact that it was Germany where anamorphosis would later find its most fertile soil. It was there that the first perspectival and catoptric anamorphic images were made, and from where Holbein started out on his way to England. It was also the homeland of Erhard Schön, the first artist to base an entire oeuvre on anamorphic images. In any case, the six drafts of the letter to Medici, and of the course the final copy, exude such a powerful Teutophobia that the possibility bears consideration. If there was a single German national Leonardo had reason to be jealous of, it was Albrecht Dürer. Although it is unlikely that the two ever met in person, each undoubtedly kept a close eye on the other’s work. In a letter (to Pirckheimer, dated 13 October 1506) Dürer recounts his plan to ride out from Venice to Bologna to meet someone who would initiate him into the secret art of perspective. If we let our imaginations run wild, we might suspect Leonardo. But a more reasoned voice suggests the Franciscan monk and mathematician Fra Luca Bartolomeo de Pacioli, a close colleague and friend of Leonardo’s, who had to make the long ride from Florence to hook up with Dürer. The meeting probably did take place, at least on the evidence of a painting by the Venetian painter Jacopo de Barbari, and provided that one is prepared to recognise the German artist in the figure of the man standing behind the monk. The painting was dated 1495 by Barbari – at least this is the customary interpretation of the enigmatic inscription “IACO.BAR. VIGENNIS. P. 1495” on a cartouche upon which an equally enigmatic fly has landed. If the young man standing next to Pacioli is indeed Dürer, this might be taken to mean that the two had met during the German painter’s first trip to Italy. While this seems unlikely, we cannot rule out the possibility that the young man was painted on the canvas later, in 1506. Truth be told, the composition would be more harmonious without that ancillary figure standing in the right corner, serving no apparent function. (The National Gallery in Washington has another portrait by Barbari, entitled Portrait of a Young Man [ca. 1505], which seems to be of the same person standing behind Pacioli, looking no older despite the passing of ten years. Perhaps this is because those ten years never passed, and the Portrait of a Young Man was painted around the same time as the portrait of Pacioli.)

More difficult to surmise is what Dürer really had in mind when he described the art of perspective as “secret” (heimlich). He could hardly have meant “perspective” in its everyday sense of “vision from a distance”, as we continue to use the word today, given that he was well familiar with the concept and had employed it widely in practice. As previously mentioned, however, the term had a far broader scope of meaning in those days, which encompassed the tricks of anamorphic representation, especially when the word perspective was accompanied by the adjective “secret”. This adjective is certainly suitable for describing the technique whereby the artist distorts an object beyond recognition, reserving the ability to reconstitute the undeformed image for a select few privy to the clever ruse. In short, it seems likely that Dürer wished to be advised on the anamorphic process by Pacioli – on techniques Leonardo investigated and with which Pacioli may have been familiar from the books of Piero della Francesca. The great geometrician of the previous generation, Piero himself had been intrigued by the problems of anamorphosis. (As I have suggested in another essay, we can argue that his Montefeltro altarpiece with the suspended egg in it, painted around 1472, rather than Leonardo’s two sketches from Milan, are the first known instances of anamorphic technique.) In fact, Piero wrote aboutanamorphosis at some length, but these writings – if we are to believe Giorgio Vasari’s allegations – were misappropriated by Pacioli and published as his own. Vasari clearly overstated his case by accusing Pacioli of plagiarism, since the latter had merely translated Piero’s discussions of perspective from Latin into the Italian vernacular, and conscientiously cited the master as the source when he published the writings. The story is nevertheless worth remembering, if only to provide the reader with a sense of the tense atmosphere surrounding the copyright of the groundbreaking invention of the “secret perspective” in those days. For his part, Dürer – later to be dubbed the “Leonardo of the North” – went to great pains to emulate Leonardo, who was nineteen years his senior, in just about everything. He learned Italian, began to parade fine expensive clothes, and let his hair grow long and wavy. The affinity between the two artists in terms of fields of interest (anatomy, natural history, fortress construction, mathematics, perspective) and pet subjects (Jerome, the Last Supper, horses, polyhedra, the Vitruvian man, the drawing machine) is so close as to deserve a separate comparative study – as would Leonardo’s hallmark knots. The Italian infinitive vincire means “to thread, to knot”. In lieu of a signature, Leonardo sometimes fitted his paintings, including Mona Lisa’s chemise, with an intricate knot pattern resembling calligraphy. More than that, he designed labyrinthine, knotted ornaments to serve as his logo, as we would call them today. Dürer copied these designs meticulously, cut them in wood, affixed his initials (A. D.), and turned a handsome profit selling the prints as his own. More likely than not, the news of his being idolised by an increasingly popular Dürer reached Leonardo himself. The old master may have allowed himself to be flattered on occasion, although his affair with his German assistants suggests that on the whole he found Dürer’s veneration dubious and vexing. We should be grateful to Dürer for those copies, because Leonardo’s original drawings did not survive. Indeed, we only know they even existed from extant copies, Dürer’s woodcuts being chief among them. Drawn in a single continuous line and possessed of intricate internal symmetries, these calligraphies bear more than a passing resemblance to the ornamentations in Islamic art. Sometimes the similarity is so striking that a comparative investigation may easily prompt one to reread the documents of Leonardo’s “trip to the East” as a genuine travelogue rather than the fictitious epistolary novel that literary historians generally claim it to be. And, while on the subject of anamorphoses anyway, we might as well do one more thing, if we feel so inclined. The pattern of the six cross-sections of knots spreads out on the sheet in exactly the same way as the netting used for the construction of catoptric anamorphoses. By placing a cylindrical mirror in the centre, we can transform the flat drawing into a quasi-three-dimensional picture.

Translation by Péter Balikó Lengyel