An exhibition of the Šechtl & Voseček Museum of Photography
The Joly process and the competing McDonough system are among the earliest additive screen processes to have been marketed commercially. Joly’s screen consists of red, green and blue-violet lines about 0.12 mm wide. Left: the original photograph; centre: the restored screen colours; right: the demosaiced colour reconstruction.
The technique built on the line-screen processes of the 1890s, but produced its fine colour screen photographically with bichromated colloid rather than by mechanical ruling. The patent was filed in 1901 and granted in 1905; when the process was shown at the first exhibition of the Society of Colour Photographers in 1907, Nature highlighted the exceptional fineness of the screen and the precise meeting of the coloured lines without gaps or overlaps. Left: the original photograph; centre: the restored screen colours; right: the demosaiced colour reconstruction.