This post explores the use of the camera obscura as an Early Modern astronomical instrument and shows how that apparatus helped make sequential images of extraordinarily controversial cosmological significance centuries before chronophotography. What follows is the story of how, in the early 17th century, Galileo Galilei literally turned his telescope upside down and used it like a rotoscope/time-lapse camera obscura to make a few heretical observations about the sun, positing yet another antecedent to the animated film and locating it at the very roots of modern science.

Soon after his 1610 publication of Starry Messenger (Siderius Nuncius)—the first treatise to detail astronomical observations made using a telescope—Galileo shifted his attentions from the night sky to the sun. More specifically, the astronomer began eyeing sunspots, the transient marks that are now understood as temperature deviations on the surface of the sun. Although it was a difficult and painful prospect—possible for only brief intervals—Europeans, following Galileo’s study of the moon, began aiming their telescopes directly at the sun in the early 17th century. With the sun magnified, previously unseen spots soon came into view (see fig. 1).

In the West, any solar irregularity such as marks on the sun suggested an unthinkable heresy. Long upheld as holy doctrine, Aristotelian cosmology assumed perfect heavenly bodies orbiting an imperfect Earth. Therefore, when Europeans first spotted sunspots (which could sometimes be seen without an instrumental aid), they tended to ignore or misidentify them. Perhaps belief conditioned sight, or prudence impeded investigation. Kepler mistook a sunspot for the transit of Mercury in 1607 (van Helden, 1996, 360), and when Christoph Scheiner observed sunspots through a telescope three years later, he argued that it was “unfitting and, in fact unlikely, that on the most lucid body of the sun there are spots” (quoted in Van Helden, 370). The Jesuit identified them instead as solar satellites and made a series of small drawings (see fig. 2).

Acknowledging the inaccuracy of his illustrations, Scheiner wrote,

They are not terribly exact, but rather hand drawn on paper as they appeared to the eye without certain and precise measurements, which could not be done sometimes due to inclement and inconstant weather, sometimes due to lack of time, and at other times due to other impediments (Ibid).

Moreover, Scheiner made his observations at different times on different days, creating vast inconsistencies in the orientations of his drawings. Nevertheless, he recorded his findings and included his drawings in a series of anonymous letters, which were sent to Galileo, who responded with criticisms of the author’s conservatism and a priori claims. The Italian subsequently initiated his own study. However, instead of looking directly into the sun, Galileo turned his telescope around and made it into a kind of proto-animation stand.

Camera obscuras have been used for millennia by astronomers and schoolchildren to safely observe an eclipse of the sun (see fig. 3). Galileo applied a similar configuration according to a technique devised by his student Benedetto Castelli. He positioned his telescope lens upside down and focused and projected an image of the sun onto a piece of paper, which acted as both a makeshift screen and drawing surface (see fig. 4). 

By eliminating the discomfort and risk caused by staring directly into the sun, the setup enabled both sustained observation and tracings with comparatively minimal distortions. Galileo outlined the method by explaining

I have then recognized the kindness of Nature, which thousands and thousands of years ago put in place the means of having some knowledge of these spots and through them, certain great consequences. For without other instruments, the image of the Sun and the spots is carried over great distances through each small aperture traversed by the solar rays, and imprinted on any surface held up to it (Reeves and van Helden, 127).

His description of “each small aperture traversed by the solar rays,” may be a purposeful recollection of Aristotle’s observations of the solar projections through “wickerwork”, and the view of an eclipse through a “sieve,” any “broad-leaved tree” or “two hands with fingers interlaced — the first recorded observation of the camera obscura effect in the West (Forster, Problemata Book XV, 911b 6, 912b 11). Note that neither Galileo nor Aristotle mention a dark room, which is not required to project an image as bright as the sun. A magnifying glass on a sunny day also does the trick (see fig. 5).

Galileo encouraged his reader to make their own investigation and urged,

And when in a church Your Lordship sees the light of the Sun fall on the floor through some faraway broken pane of glass, hasten there with a large unfolded sheet of white paper, because you will discern spots on it (Reeves and van Helden, 127).

The Lordship he addressed was Marc Welser, who had forwarded him Scheiner’s letters and then published his responses. Galileo replied in Italian, realizing that Welser and readers in Italy were likely to know of holes purposely installed to transform churches into cameras obscura. Such holes paired with meridian lines tracked solar projections at daily intervals from solstice to solstice. Between 1575 and 1580, Dominican priest Egnazio Danti designed three such meridiana for Santa Maria Novella (Florence), San Petronio (Bologna), and the Vatican Tower of the Winds. These installations created images of the sun that could help determine the dates for Easter (which is based on vernal equinox) and confirm the newly reformed Gregorian calendar (Heilbron).

Visual evidence was therefore acceptable as scientific evidence, and Galileo had already published sequential imagery before his sunspot drawings. Starry Messenger has 65 diagrammatic observations of four stars near Jupiter, tracking their movement over time to prove that they were in orbit around the planet. It also demonstrates the mountainous quality of the moon’s surface (previously understood as smooth) by identifying its markings as shadows that shifted over time.

The tract includes 4 geometrically inaccurate but rhetorically convincing drawings of lunar phases (see fig. 6). Days after its publication, Galileo described his desire to “draw the faces of the Moon with great diligence through an entire period, and imitate it exactly, because in truth, it is a sight of the greatest wonder” (van Helden, 365). In other words, Galileo was seeking the financial support to draw, and have engraved, the complete lunar cycle in a sequence of drawings.

For his sunspot project, Galileo traced an image of the sun and its spots onto a sheet of white paper at the same time each day. To prevent distortion and keep his scale uniform, he drew circles of the same size on the paper in advance to use as registration guides. Whereas other optically-made or inspired imagery is based on arrested movement (accomplished by a short exposure time or a subject obliged to hold still), Galileo’s tracings revealed to him and to his audience transformation and motion that was otherwise imperceptible and unrepresentable. Shifts in size and shape, and then foreshortening at the edge of the solar disk supported Galileo’s argument that the sunspot were in flux and very close to, or part of, the sun and not the shadows of solid bodies in transit or orbit—a radical proposition that would lead to his Inquisition. That the sun was surrounded by an inconsistent surface or layer and was possibly spinning, challenged the doctrine of an immutable heavenly body and gave credence to a Copernican heliocentric universe. Science historians Eileen Reeves and Albert van Helden describe his shift from drawing after direct observation to tracing projections as “the transition from opportunity-driven qualitative observation to systematic (and quantitative) research on sunspots” (82). Why not also describe Galileo’s first and only foray into drawing the moon and the sun as a scientific method, as early pre-cursors to animation, to rotoscoping and to time-lapse photography? That would also identify his telescope as another motion picture projection device that operated long before cinema, and a heretical one at that.

This is an abridged version of a paper presented at the Society for Animation Studies annual conference at the University of Padua in June 2017.

 

Alison Reiko Loader specializes in digital animation and feminist media history. She holds a PhD in Communication and has taught at Concordia University since 2001.

 

References

Forster, E. S., translator. “Book XV: Problems Connected with Mathematical Theory.” The Works of Aristotle, Volume VII: Problemata, Clarendon Press, 1927.

Heilbron, J. L. The Sun in the Church: Cathedrals as Solar Observatories. Harvard University Press, 2001.

Hockney, David. Secret Knowledge: Rediscovering the Lost Techniques of the Old Masters. New and expanded ed, Thames & Hudson, 2006.

Lefèvre, Wolfgang. Inside the Camera Obscura: Optics and Art under the Spell of the Projected Image. Max-Planck-Inst. für Wissenschaftsgeschichte, 2007.

Reeves, Eileen Adair, and Albert Van Helden, editors. On Sunspots. University of Chicago Press, 2010.

Steadman, Philip. Vermeer’s Camera: Uncovering the Truth behind the Masterpieces. Oxford University Press, 2001.

Tim’s Vermeer. directed by Teller, performance by Tim Jenison, Penn Jillette, Martin Mull, David Hockey, Philip Steadman. Sony Picture Classics. 2013.

van Helden, Albert. “Galileo and Scheiner on Sunspots: A Case Study in the Visual Language of Astronomy.” Proceedings of the American Philosophical Society, vol. 140, no. 3, 1996, pp. 358–96.

—. “The Galileo Project | Science | Sunspots.” The Galileo Project | Science | Sector, Rice University, 1995, galileo.rice.edu/sci/observations/sunspots.html.