Making Color Images from Prokudin-Gorskii's Negatives

There is no known replica or illustration of the camera that Prokudin-Gorskii used. It was a view camera of his own design, perhaps similar to a model [left] designed about 1906 by Dr. Adolf Miethe, whom Prokudin-Gorskii had met previously in Germany.

Miethe, Adolf, 1862-1927.
Camera and Casette, ca. 1906.
Illustration from Fotograf-Liubitel 17, no. 12 (December 1906): 5.
General Collections, Library of Congress

We know that Prokudin-Gorskii intended his photographic images to be viewed in color because he developed an ingenious photographic technique in order for these images to be captured in black and white on glass plate negatives, using red, green and blue filters. He then presented these images in color in slide lectures using a light-projection system [right] involving the same three filters.

Lantern Projector
Thomas Cradock Hepworth.
Book of the Lantern.
New York: Edward L. Wilson, 1889.

A single, narrow glass plate about 3 inches wide by 9 inches long was placed vertically into the camera by Prokudin-Gorskii . He then photographed the same scene three times in a fairly rapid sequence using a red filter, a green filter and a blue filter.

When viewed through Prokudin-Gorskii’s camera, the scene being photographed would have appeared upside down and reversed from its actual orientation.

Left: Photograph of Glass Plate
Right: Inverted View Through Camera Lens

For the digital process, the original tri-part glass negative is scanned with an overhead digital camera in grayscale mode. Image-editing software converts the scan of the entire plate from negative to positive form. The scan is inverted to represent the original physical orientation.

The entire plate is then reduced to 8-bit grayscale mode. Under magnification, the quality of each image on the plate is reviewed for contrast, degree of color separation, extent of damage to the emulsion, and any other details that might affect the final color composite.

The scan of
the entire plate
is aligned and
the outside edges
are cropped.

An electronic file is created for each image from the cropped tri-part plate forming three separate “layers” from which the final color composite will be generated. The layers are labeled by color.

While still in grayscale mode,
the red(R), blue(B), and green(G) layers are aligned forming the “RGB” color composite.

This registration process is
the most difficult step.

The RGB (Red, Green, Blue)
color composite is cropped
to eliminate all but the photographic area shared
in common by
all three layers.

The cropped color composite
is adjusted overall to create
the proper contrast,
appropriate highlight
and shadow detail,
and optimal color balance.

Final adjustments may be applied to specific, localized areas of the composite color image to minimize defects associated with over or underexposure, development, or aging of the emulsion of Prokudin-Gorskii’s original glass plate.

The completed color
composite is retouched
to minimize defects
associated with age
and incidental damage.

The glass plate negatives used in this demonstration:

Prokudin-Gorskii, Sergei Mikhailovich,
1863-1944, photographer.
“The Bukhara Emir”

Prints and Photographs Division
Library of Congress.
Reproduction number: LC-P87-8086A-2

The glass plate negatives used in this demonstration:

Prokudin-Gorskii, Sergei Mikhailovich,
1863-1944, photographer.
“Pinkhus Karlinskii. Eighty-four years [old].”

Prints and Photographs Division
Library of Congress.
Reproduction number: LC-P87-5006