Augustus, not Caligula

Photography in the Service of Historical Analysis 

I like photography, ancient history and computer programming. These interests intersected in a recent project involving the Getty Augustus, an ancient Roman portrait head of Rome’s first emperor. 

Over the years  scholars have concluded that this marble head,  on display at the Getty Villa in Malibu, was, like a dozen other portraits of Augustus, recarved from an earlier  portrait of Caligula, Augustus’s great grandson, after Caligula was murdered. Using photography of several types, along with software written by me and some very cool commercial CAD/redesign software, I’ve shown that despite some evidence supporting this conclusion, it simply cannot be correct. 

Scholars and historians including Klaus Vierneisel, Paul Zanker, Hans Jucker and Jiri Frel have given evidence for the reworking of Caligula’s features into those of Augustus that we now see on the marble head. The evidence includes reshaping its mouth in order to correct Caligula’s receding lower lip, reshaping Caligula’s weak chin, and some claw chisel marks from removal of Caligula’s mullet haircut from the nape of what would become Augustus’s neck. They also observed that the current sculpture still retains Caligula’s wide eyes and hollow temples, traits not found, they say, in original marble portraits of Augustus. 

Careful photography of many portrait specimens of both subjects shows otherwise. Augustus’s temples are just as hollow as those of Augustus, and Caligula does not have a weak chin, at least in comparison to Augustus. To prove this my wife and I shot photos of sufficient detail, with appropriate photographic technique to accurately identify facial landmarks and measure distances between them in the frontal and profile planes.  Appropriate photographic technique is a major factor here. Expensive, respected catalogs of these ancient heads are on the shelves of every archaeologist and Roman art historian. At best the photos in these catalogs were done with standard portrait techniques that would be used on human heads - lenses in the 85 to 135 mm range with Rembrandt, “loop” or other lighting styles that make humans look good. The worst the catalog photos look like they were done with an iPhone at a distance of about a foot. The perspective effects (so-called perspective distortion, although this isn’t really lens distortion, it’s the consequence of projecting a bumpy, nominally-spherical surface onto a plane) are grotesque – rather like the in-your-face view of the Getty Augustus at right above. 

Unfortunately, in the era of iPhone photography, viewers are now more accepting of wacky wide angle faces, and the unsuitability of photos in catalogs of Roman portrait heads isn’t noticed by most scholars. Also, portrait lighting is designed to deceive and shape the viewer’s perception with shadows – not really a good thing for rigorous analysis. 

Instead of using their bubble-headed shots, we took our own – over 30,000 of them.  We used full-size sensor 35mm cameras with 200 to 400 millimeter lenses, being very careful about frontal and profile facial plane alignment. Then I wrote some c# code to display the images so I could click on the facial landmarks used by plastic surgeons for measuring key facial proportions and have the software do the calculations. Armed with all this data, I can very objectively state that Caligula’s temples are no more hollow than Augie’s, and that Augustus’s chin is weaker than Caligula’s. So the condition the scholars saw as evidence of recarving doesn’t really support that claim, because it doesn’t exist in the first place.

I suspect that the weaknesses of photos in portrait catalogs subtly interacted with scholars’ memories of the ancient historian’s attempt to color our impression of the hated Caligula. These historians were either senators or were closely tied to senators – a group highly motivated to paint Caligula as an insane tyrant. Suetonius, for example, reports of Caligula, “oculis concauis” (sunken eyes). The ancients were prone to belief that there was a close link between appearance and character. Suetonius goes on to describe Caligula’s appearance in terms obviously derived from his preconceived ideas of the emperor’s character, followed with details of his debauchery. This, and perhaps the image of John Hurt as Caligula in a gold bikini in the BBC presentation of Robert Graves’ I Claudius, is just too difficult to ignore subjectively – which is why I let software measure up the heads.

I used another form of photography in this work too. The Polhemus FastScan Scorpion laser scanner has the novel ability to build a wireframe of a subject in real time without ever touching the surface of the sculpture and without needing to use a turntable. This was enough for the Getty Museum to give us access to there collection so we could build accurate 3-D models of some heads. Scanning is actually a photographic process, although the photo data is converted to geometric data in real time to build the model. I look forward to a time when software is able to build accurate 3-D models from a collection of normal photos. Microsoft’s Photosynth project appears to be headed in that direction.

High-tech analysis showed us that there was no way that a Caligula head shaped like any of the known specimens could have been reworked into the Getty Augustus, but inspection of the Getty head shows that it clearly was recarved from some other head. Upon seeing our data, John Pollini at USC, who has studied thousands of such pieces in great detail, immediately suggested an answer. Using superimposition of a bunch of photos, we showed that his guess was right on the money – the original portrait was of Octavian, an earlier version of Augustus. See the video for a lot more detail and some neat animations.

[This is an HD video, so you can use the buttons on the player to see it in native resolution or full screen.]