Tacita Dean’s current installation in Tate Modern is a homage to the dying art of creating images on celluloid film, before it is completely killed off by digital media. It’s a compilation of film clips blown up to enormous scale to show features unique to that medium, such as sprocket marks, scratches etc. For her, this installation is a way of expressing the skills and technologies needed to create images on film.
There’s been a fair amount of debate recently about the imminent demise of film, and what that might mean for the arts of photography and movie-making. But very little has been said about the equally long history of using film as an essential part of scientific experiments, and how this era is also coming to an end.
Astronomical images used to be recorded as drawings, before photography took over in the late nineteenth century. Some telescopes, such as the Schmidt, had an extraordinarily large field of view, and used glass photographic plates (the plates were about 3mm thin so they could be curved in the focal plane of the telescope) to obtain information on 100,000 objects in one image. Until recently, to use digital devices such as CCDs for large field of view images would have been prohibitively slow and expensive.
So, what are the implications of replacing this medium with digital images? Well, astronomy is already so virtual. For a physical science that is concerned about the nature of matter in the universe, it has precious little actual matter to get its hands on. Apart from meteorites and the small number of Moon samples, practically the whole of the rest of astronomy is done using images. Everything we know about the birth, evolution and death of stars, the formation of galaxies, the Big Bang itself, is from images. At optical wavelengths, these images used to be photographs in which the actual light from stars and galaxies was captured and stored in the silver grains. Now, the images are electronic, and the light generates electrons in the digital detectors which are then read out to a computer for future manipulation and storage. The light itself is not recorded, we don’t keep anything of the actual objects we’re looking at. We’ve distanced ourselves by another step from the rest of the Universe.