The second half of the nineteenth century saw the progression from early experiments with light-sensitive compounds to the first cameras and photographic films becoming available to the general population. It developed from the minority use of the camera obscura as a painter's tool, through the first fleeting glimpse of a photographic image in a beaker containing silver compounds after light exposure, to the permanent rendering of the image, and then to the invention of the negative–positive photographic process used today to produce an archival image. A camera using roll film, the Kodak, was available to the public in 1887 and brought photographic media to the masses. By the beginning of the twentieth century, silver halide materials were produced that were sensitive to all visible wavelengths in the electromagnetic spectrum, producing tonally acceptable images, and this paved the way for practical colour imaging processes, beginning with the Autochrome plate in 1907, to be developed.