Canton, Group of British Officers inthe garden of the allied commissioners' Yamun 1859

This stereograph shows British officers in Canton, and was made by Pierre Joseph Rossier using a twin-lens camera. With this device, he captured two nearly identical images simultaneously, giving a three-dimensional effect when viewed through a stereoscope. The process of creating such an image was complex. It involved coating a glass plate with a light-sensitive emulsion, exposing it in the camera, and then developing the negative in a darkroom, using a variety of different chemicals. Finally, it was printed on paper. Each step required careful control and skill. What’s interesting is that this was not simply a technological feat, but an intensely social one. The officers in the picture were certainly aware of the photographic process, and of the technology’s perceived objectivity. This brings into sharp relief the amount of work involved in creating an image that presents itself as effortlessly real. In this case, the photograph documents British power in China. It reminds us that all visual media are made, not born, and are shaped by both technical considerations and political will.