Early Photographic Processes

Autochrome

1907 - 1940

Discovery

The autochrome process was discovered by the brothers Auguste and Louis Lumiere of Lyons in France.  It was  patented in 1904;  1906 in the USA. 

The process was made commercially available from 1907 until about 1940.

Process

Autochrome was the first generally available process for colour photography.

The Lumiere brothers' company sold Autochrome glass plates is sizes from under 2 ins x 2 ins up to 15 ins x 18 ins.

Creating the Plate

1.  To create the plates:

a)  miniscule grains of potato starch were died, some green, some red-orange, and some blue violet, then all three colours were well mixed.

b)  the glass slide was coated with varnish, then a thin layer of the mixed coloured starch was added.

c)  a further coat of varnish was added.

d)  the slide was then coated with a layer of orthochromatic gelatin bromide emulsion.

Exposing the Plate

2.  The slide was exposed in the camera, with the emulsion side furthest from the lens, so that the light had to pass through the starch before reaching the film.  [The starch acted as a filter and so recorded the intensity of light in each of the three colours.

Processing the Plate

3.  The plate was then processed in the darkroom to produce a slide with a positive image (i.e. developed, washed, bleached, exposed, re-developed, washed and fixed).

For further comments see 'In Edinburgh - 1910' below

Result

The Image

The autochrome process produced a coloured transparency on glass, with luminous colours.

©

It can be viewed by holding the slide up to the light or by projecting its image onto a screen. 

The grains of starch gave autochromes a pointillist appearance.

In Edinburgh 

1870s - 1900s

The concept of colour printing was not new to the Members of Edinburgh Photographic Society when the autochrome process became available.

EPS Members had discussed colour photography at its Wednesday Meetings:

-   on 6 occasions in the 1870s

-   on 5 occasions in the 1890s.

-   on 5 occasions in the 1900s.

A demonstrated of the autochrome process was given to the EPS Optical Lantern Section on 11 March 1908.

1910

1.  In the EPS Open Exhibition in 1910, one of the four Classes was for "Photographs in Colour (any process)".

2.  In the EPS Members' Exhibition in 1910, one of the nine Sections was for ""Colour Work".  No prizes were awarded for this Section.  I don't know whether or not the Section had any exhibits.

3.  W Inglis Clerk gave a lecture to EPS on Saturday 5 March, entitled Photographs in Natural Colours.  He described his use of the Autochrome process, including:

Exposure

-  Treat the slide carefully.  It is very delicate.

-  Polish the back of the plate carefully to remove all dirt

-  Exposing the slide - recommend 2 seconds at f8

Processing

-  Process in the darkroom under a green (rather than ruby) light.

-   Develop (Rodinal , 1 in 10),  rinse, use permanganate reversing solution,  rinse, expose to light until black, rinse,  dry,  varnish.    Normally no need to fix or intensify.

W Inglis also referred briefly to the Omnicolore plate which he said required about half the exposure of the Autochrome, gave more brilliant colours and was suitable for gloomy weather.

1910s - 1930s

There were 18 autochrome entries, amongst the total entry of 227 photos in the EPS Open Exhibition, 1912.

In the EPS Members' Exhibition, 1913, it was reported that "all classes were well represented, none more so than the autochromes."

On 3 December 1919, W E Redding gave a lecture titled Some Autochrome Pictures.

EPS continued to discuss colour photography at its Wednesday Meetings:

-  on 9 occasions in the 1920s.

-  on 3 occasions in the 1930s.

However other colour materials had become available by the 1930s.

In 1936:

-  Kodachrome started to market their Kodachrome film in 35mm format, having first introduced for home movies in 1935.

-  Agfacolor began to sell their colour film.

In 1937:

-  A lecture titled: A Selection of Lantern Slides in Dufraycolor was given to Edinburgh Photographic Society by WJ Sharp.

Acknowledgements:  USA Patent details:       bway.net web site
in Edinburgh 1910 Lecture:     Transactions of EPS:  April 1910,  pp 7-8
in Edinburgh (other)      Wide range of EPS literature
Background info on the process:  Looking at Photographs (Gordon Baldwin)