We theorize that some Paleolithic engravings on small stones and bones hold direct tracings of images projected inside a hide tent camera obscura. Though these engravings are numerous and widespread they do not enjoy the recognition of the famous deep cave paintings. Tracing a moving image of a living animal is a very odd way of working and creates a distinct set of characteristics, including multiple legs and heads, as well as inexplicable blank areas, which combine to create astoundingly immediate and lifelike artworks, a signature of portable Paleolithic art. What we see in the deep cave is the visual lexicon of the daylight tent-camera process sometimes being applied to cave walls, but this is a matter of translation, of applying a visual logic developed in the tent. Deep cave use of a camera obscura is NOT part of the paleo-camera theory.

The method an artist chooses directly impacts the look of the art. We wanted to compare the characteristics of different drawing methods: memory, observation, and tracing a live action projection.

Students were first asked to draw a bison from memory. The memory drawings were collected. Video footage of bison meandering around a field was then projected onto the far wall of the room and students were instructed to draw a bison from observation. The observation drawings were collected. The projector was then turned upside-down (mimicking the projection inside a camera obscura) and students were instructed to trace the bison. Below are the drawings of student Jared Frenzel-Sulyok.

The memory and observation drawings vary only slightly, with the observation drawing having a more proportional head and increased fur. The tracing, however, takes on a completely different look. It has two tails and two heads, which describe the movement of the animal during the course of the tracing.

Comparing the results of the drawing experiments with actual Paleolithic plaquettes (small portable engraved stones and bones), it is notable that both sets share repeated features that describe movement. On the left below are engravings from Paleolithic plaquettes: a mammoth from Gönnersdorf, Germany and a horse from Laugerie Basse, France. On the right are two of the tracings from our experiments.

It is important to note that in our experiments no student drew a nine legged bison from memory or observation. However, repeated features became routine in the moving image tracings. There are two factors that cause the repeated features: first, of course, is that the subject moves and second is that the artist cannot see the line as he makes it. The light of the image overpowers any information on the drawing surface. Being unable to see one's own line is very peculiar, it causes some areas to be repeated and some to be missed entirely. The invisibility of the lines in process has a distinct effect on the drawings, a distinctly Paleolithic effect, an indication that perhaps paleo-peoples sometimes used a traced projection method.

Another tell-tale characteristic of a projected image is keystoning, the distortion that occurs when the projection surface is tilted out of parallel from the image source. Below is a tracing by student Nate Jones, where he tilted the drawing board out of parallel making bison's muzzle extend out.

Keystoning is also evident on certain Paleolithic plaquettes. Below is an engraving of a horse from Le Mas d'Azil, France.

The lines highlighted in red show the morphologically correct horse. The lines highlighted in green show a distorted underbelly and lengthened rear leg. On the left below is horse from the cave of Lascaux. On the right is the image of a living horse projected inside a camera obscura onto a tilted stone plaquette.

The extremely small heads and enormous midriffs of some Paleolithic artworks have been confounding, because no animal in the fossil record is known to have been so disproportioned. We propose that the source of certain Paleolithic stylized features can be found inside a hide tent camera obscura.