Shadows of Expectation: Robert Hooke’s Picture Box and the Visual Economy of Projection
On December 19, 1694, eminent British natural philosopher Robert Hooke presented a paper to the Royal Society of London on “An Instrument of Use to Take the Draught, or Picture of Any Thing.” Famous for his work on optical instruments and the study of light, among many other things, the fifty-nine-year-old “England’s Leonardo” had, basically, just tweaked an ancient invention. What he presented to his fellows—a congregation of physicians, clergymen, noblemen, academics, and men of affairs—was a portable camera obscura. Hooke himself was quick to acknowledge that his invention was not exactly a “Thing that [had] never been done before.” Camerae obscurae were originally literally dark chambers, equipped with a small aperture at one wall through which inverted light images were pro- jected on the opposite wall. These chambers had been used in the study of light and shadow at least since the experiments conducted by the Arab mathematician Abu Ali al-Hasan Ibn al-Haytham circa 1000 CE, with a smallish box about 1.30 meters tall. By the seventeenth century in Europe, camerae obscurae had become key instruments in all sorts of scientific inquiries, in addition to aiding artists in tracing the outlines of objects and rendering shadows and tonal values. Significant developments to the design of these devices had also been made. Around 1670 in England, Robert Boyle, for whom Hooke worked as an assistant during the period, described his “portable darkened roome,” a box camera equipped with an adjustable lens that afforded sharp projections of “Motions … Shapes and Colours of outward Objects” onto a sheet of paper.4 Across the Channel, the German Canon of the Premonstrate Order Johann Zahn provided the readers of his 1685 book Oculus artificialis with a variety of technical illustrations of portable camerae obscurae.