Autochromes Lumière
The technological process > Method of Use > Taking the Picture

 

Taking the Picture

Placement in the Chassis
Autochrome plates could be used with most of the standard materials available at the beginning of the century for monochromatic photography: the larger wooden cameras, lighter cameras designed for travelling, not to mention the panoramic and stereoscopic cameras which had been so popular since the 1870's and 80's.

The addition of a yellow filter, which had to be placed in front of the lens to compensate for the panchromatic panchromatic
Sensible to all the wavelengths of the visible spectrum, from violet to red.
emulsion's over-sensitivity to blue light, was the only necessary modification. In addition, the plate had to be inserted backwards, reversing the conventional direction. This way, light entering the camera would first pass through the colored screen layer of starches before making its impression on the photosensitive emulsion. Failing to reverse the plate meant that the light registered directly upon the photosensitive layer without being filtered by the coloured starches, producing a standard monochromatic image.

Exposure Time
The absorption of light by the  colored screen, associated with the constraints associated with the sensitive layer, did not quite allow one to reach the level of sensitivity of the monochromatic processes of the time. Taking an Autochrome image with standard equipment on a bright summer day typically required an exposure time of about one second, so "the cameras had to be equipped with a tripod to provide stability throughout exposure."

Under identical conditions, a photographer operating in back and white, with the Lumière's celebrated Etiquette Bleue extra-rapide plates for example, could take a snapshot by hand at 1/50 or 1/100 of a second. So, the Autochrome's low sensitivity may have curbed the enthusiasm of many photographers, who were not ready to give up the advantages the industry had brought them over the years. Nevertheless, its speed led to the development of a unique aesthetic of the Autochrome itself, adding the realism of colour to the photographic references of the 19th century

In the years which followed the introduction of the Autochrome, many hyper-sensitisation formulas were developed and published in specialist journals, leading to an improvement of the photo-sensitivity of the plates. Sometimes this was to the detriment of the resulting image however, if it was altered through the dominance of some of the hue.