More is known of Colonel Mervyn O’Gorman's career as an electrical & aircraft engineer (please visit wikipedia) yet his artistic interests turned him into one of the pioneers in an early color photography process known as Autochrome. Whilst the autochrome process did not produce the earliest color photographs - Scottish physicist James Clerk Maxwell had experimented with color photography as early as 1861 - it was the first industrialized technique of color photography to be used, with relative ease and with attractive results, by amateur photographers.
It was a process invented by the brothers Auguste and Louis Lumiere of Lyons in France, who are perhaps more well known for their 1890s invention, the "Cinematograph", a motion picture film camera, which also served as a film projector and printer. The Autochrome process was patented in 1903, but made available to the public in 1907, decades before the advent of Kodachrome and Agfacolor in the 1930s.
An autochrome plate was created by covering a glass slide with a mixture of crude pine sap and beeswax, and then coated with a "mosaic filter layer" of microscopic grains of potato starch dyed to the 3 primary colors: red-orange, green, and blue-violet. The colors were mixed together to create a random color mosaic of the grains, and were flattened to reduce graininess and increase light transmission. Lampblack was then applied, to fill the clear spaces between the grains. After this, the plate was coated with shellac, and dried, so as to protect the color mosaic and to provide a flat surface for a panchromatic silver halide emulsion, which is sensitive to all wavelengths of visible light .
Unlike ordinary black and white plates, the autochrome plate was placed in the camera with the glass side nearest the lens. When the photograph was taken, the light from the object came through the lens and the glass backing of the plate, and was filtered by the color mosaic of dyed potato starch. The blue-violet stained grains let blue-violet light through, the green-stained grains let green light through, and the red-orange stained grains let red-orange light through. Other colors, made of mixtures of those primary colors, would allow mixtures of light through. Because the photographic emulsion wasn't sensitive to all colors equally, a yellow filter was used in the front of the lens.
Because of the light loss due to all the filtering, Autochrome plates required much longer exposures than black-and-white plates and films, which meant that a tripod or other stand had to be used and that it was not practical to photograph moving subjects.
The Autochrome plate was reversal-processed into a positive transparency in the darkroom. That is, the plate was first developed into a negative image but not "fixed", then the silver forming the negative images was chemically removed, then the remaining silver halide was exposed to light and developed, producing a positive image: a colored transparency on glass with luminous colors. The images could be viewed by holding the slide up to the light or by projecting its image onto a screen.
The silver halide layer and the mosaic filter remained precisely aligned and were distributed together, so that light was filtered in situ. Each starch grain remained in alignment with the corresponding microscopic area of silver halide emulsion coated over it. When the finished image was viewed by transmitted light, each bit of the silver image acted as a micro-filter, allowing more or less light to pass through the corresponding colored starch grain, recreating the original proportions of the three colors. At normal viewing distances, the light coming through the individual grains blended together in the eye, reconstructing the color of the light photographed through the filter grains.
The color photographs that you see here are of his Mervyn's daughter Christina, taken in 1913, and have been shown in exhibitions on early photography, including the UK Science Museum's Drawn By Light exhibition, which featured more than 200 images selected from the archives of The Royal Photographic Society’s national collection.
The National Media Museum writes that Christina’s choice of red outfits in the portraits was a good one, as the color was captured particularly vibrantly by the Autochrome process.
To me these beautiful photographs, made with slower exposures and larger apertures, embody a Pre-Raphelite-esque aesthetic, which provide a welcome relief to the 'sharp' photography of today. Enjoy!