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lithography. In 1848, Lion opened an art school in New
Orleans and in 1865, a year before his death, he became
professor of drawing at Louisiana College.
Bob Zeller
LIPPMANN, GABRIEL JONAS
(1845–1921)
French scientist and physicist
Lippmann who was born in 1845 is known for many
fundamental contributions in several scientifi c fi elds:
electricity, thermodynamics, optics, photography, and
photochemistry. He became interested in the theory of
light and, in particular, color theory. As early as 1886,
he had developed a general theory of recording colors as
standing waves in a light sensitive emulsion. However,
most of his time was devoted to perfecting a suitable
recording emulsion for his experiments. The fi rst plates
that Lippmann used were albumen emulsions contain-
ing potassium bromide. The plates were sensitized in a
silver bath, washed, fl owed with cyanine solution and
dried. The sensitivity was extremely low. On February 2,
1891, Lippmann announced at the Academy of Sciences
in Paris that he had succeeded in recording a true-color
spectrum which was permanent. A little more than one
year later, on April 25, 1892, Lippmann gave a second
presentation at the Academy of Sciences. This time he
displayed four color photographs of different objects.
Later he was able to record a landscape with a grey
building surrounded with green foliage and blue sky.
The size of his early photographs was 4 cm by 4 cm
and later 6.5 cm by 9 cm. Lippmann developed the fi rst
theory of recording monochromatic and polychromatic
spectra in a panchromatic b/w emulsion. He applied
Fourier mathematics to optics, which was a new ap-
proach at that time. His color photography technique
is known as Interferential Photography or Interference
Color Photography, however most often referred to as
Lippmann Photography.
The principle of Lippmann photography is clear.
Because of the demand for high resolving power in
making Lippmann photographs, the material had to be
a very fi ne-grain emulsion and, thus, of very low sen-
sitivity. The coating of emulsion on Lippmann plates
was brought in contact with a highly refl ective surface,
mercury, refl ecting the light into the emulsion and then
interfering with the light coming from the other side
of the emulsion. The standing waves of the interfering
light produced a very fi ne fringe pattern throughout
the emulsion with a periodic spacing of λ/(2n) that had
to be recorded (λ is the wavelength of light in air and
n is the refractive index of the emulsion). The color
information was stored locally in this way. The larger
the separation between the fringes, the longer was the
wavelength of the recorded part of image information.
When the developed photograph was viewed in white
light, different parts of the recorded image produced
different colors. This was due to the separation of the
recorded fringes in the emulsion. The light was refl ected
from the fringes, creating different colors correspond-
ing to the original ones that had produced them dur-
ing the recording. It is obvious that there was a high
demand on the resolving power in order to record the
fringes separated in the order of half the wavelength of
the light. It was also clear that the processing of these
plates was critically important, as one was not allowed
to change the separation between the fringes because
that would create wrong colors. In order to observe the
correct colors in a Lippmann photograph, the illumina-
tion and observation have to be at normal incidence. If
the angle changes, the colors of the image will change.
This change of color with angle is called iridescence
and is of the same type as found in peacock feathers
and mother of pearl.
Soon after Lippmann had introduced his technique
several scientists and researchers began to explore and
further develop this new color photography technique.
Auguste and Louis Lumière produced a special ultra-
fi ne-grain silver halide recording emulsion which had
a much higher sensitivity than Lippmann’s fi rst emul-
sion. With the new emulsion Louis Lumière was able
to recorded the fi rst color portrait in 1893. In Germany
Richard Neuhauss and Hans Lehmann contributed ex-
tensively to the development of Lippmann photography
and both recorded excellent color photographs at the
end of the 19th century.
Although Lippmann photography is extremely in-
teresting from a scientifi c point of view, it was not very
effective for color photography since the technique was
complicated and the exposure times were too long for
practical use. The diffi culty in viewing the photographs
was another contributing factor, in addition to the copy-
ing problem, which prevented Lippmann photography
from becoming a practical photographic color-record-
ing method. However, one-hundred-year-old Lippmann
photographs are very beautiful and the fact that the
colors are so well preserved indicates something about
their archival properties. Still today, it is the only pho-
tographic technique that can record the entire color
spectrum of a scene, rendering extremely realistic e.g.,
human skin and metallic refl ections. When the Lumière
brothers introduced the more practical Autochrome color
process in 1907, the interest in Lippmann photography
disappeared. However, in the late 1990s, a new inter-
est in Lippmann’s technology has been manifested by
newly recorded Lippmann photographs (without the
need for mercury) as well as several recent publications
on interference color photography.
Hans I. Bjelkhagen