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acceptance as an objective tool. As photography became
capable of recording increasingly narrow slices of time,
it grew in versatility and status. Ultimately audiences
came to understand that photography was capable of
making pictures far more penetrating than traditional
media such as drawing, painting, and printmaking.
Instantaneous photography—and with it, the ability to
make images of fl eeting and ephemeral subjects—be-
came a central element of photographic aesthetics.
Phillip Prodger
See also: Muybridge, Eadweard James; Camera
Design: Stereo Cameras; Dallmeyer, John Henry &
Thomas Ross ; Wilson, George Washington; Stuart
Wortley, Henry Archibald; Daguerre, Louis-Jacques-
Mandé; Niépce, Joseph Nicéphore; Talbot, William
Henry Fox; Herschel, Sir John Frederick William;
le Gray, Gustave; Bacot, Edmond; Llewelyn, John
Dillwyn; Frenet, Jean Baptiste; Nègre, Charles;
Tournachon, Adrien; Adamson, John; Hill, David
Octavius, and Robert Adamson; Piazzi Smyth,
Charles; Anthony, Edward, and Henry Tiebout;
England, William; Blanchard, Valentine; Sommer,
Giorgio; Watkins, Carleton Eugene; Bertsch, Auguste-
Adolphe; Animal and Zoological Photography;
Llewelyn, John Dillwyn; Haes, Frank; Dubois de
Nehaut, Chevalier Louis-Pierre-Theophile; Marey,
Etienne Jules; Anschütz, Ottomar; and Londe, Albert.Further Reading
Aubenas, Sylvie and Gunthert, André, La révolution de la photog-
raphie instantanée, 1880–1900, Paris: Bibliotheque nationale
de France and Société Française de Photographie, 1996.
Gernsheim, Helmut, “Instantaneous Photography,” in The Rise
of Photography, 1850–1880: The Age of Collodion, London:
Thames & Hudson, 1988.
Gunthert, André, “La conquête de l’instantané: Archéologie
de l’imaginaire photographique en France (1841–1895),”
Ph.D. diss., École des Haute Études en Sciences Sociales,
Paris, 1999.
Herschel, John, “Instantaneous Photography,” Photographic
News 4 (May 1860): 1.
Howlett, Robert, “On Taking Instantaneous Pictures,” Photo-
graphic Notes 3 (1 January 1858): 11–12.
“On Instantaneous Exposures, and Improved Means for Effect-
ing Them,” British Journal of Photography 13 (12 January
1866): 13–14.
Prodger, Phillip, Time Stands Still: Muybridge and the Instanta-
neous Photography Movement, New York: Oxford University
Press, 2003.
Thompson, Stephen, “Instantaneity,” Photographic News 15 (3
March 1871): 102–3.INTENSIFYING
In 1867, Photographic News deplored the practice of
intensifying under-exposed negatives. “We disapprove
... we consider it bad practice ...,” stated an editorialwhich argued that correct exposure produced the perfect
negative, and “all those harsh black and white speci-
mens” would be eliminated. Nevertheless, uncertainty in
exposure encouraged a search for treatments to retrieve
thin negatives. Intensifi cation increased the effective
sensitivity of the camera material, and was applied to
daguerreotypes, collodion plates and dry plates.
The Becquerel effect was found to be suitable for
improving underexposed daguerreotype plates. In 1840,
after re-exposing plates to yellow and red light, Ed-
mond Becquerel had found that he could strengthen the
original image by development with mercury, although
Claudet found that the benefi t was restricted to plates
of silver iodide.
Frederick Scott Archer favoured a bleaching method
whereby the silver image of a processed collodion nega-
tive was treated with mercuric chloride, which formed
a white precipitate and strengthened the image-forming
deposit.
Adjusting the colour of the negative would often im-
prove its actinic properties in printing. In 1865, Herman
Selle mixed potassium ferricyanide and uranium nitrate
to produce a brown colouration and although effective,
no further research was done for ten years, when a pre-
cipitate (of silver ferrocyanide and lead ferrocyanide)
was “blackened” in a dilute solution of ammonium
sulphate. Because such treatments were often applied
out of necessity, the ensuing print quality was poor and
of excessive contrast.
By 1861, intensifying was better understood, allow-
ing the developed image to be modifi ed after drying.
The formulas claimed to have infl uences on tonality
and contrast, with preferential action in the shadows,
and some, such as chromium intensifi er, also darkened
prints.
With gelatine emulsions, intensifi cation remained
a darkroom procedure when developing plates with
insuffi cient density. There were different methods, each
with a “printing value.” For example, chromium would
bleach the negative for re-development to a value of
1.5, whereas a mercuric chloride bleach, followed by
redevelopment in ferrous oxalate, improved the printing
value 2 times. Solutions containing mercuric iodide,
lead, uranium, copper bromide were widely used, but
the most popular were the mercurial processes, with
values of 3.
Once dry plates were established, two non-chemi-
cal ways of intensifying the latent image emerged.
William Blair had proposed a technique in 1869 which
ensured “acceleration of exposures” by demonstrat-
ing that, before development, the latent image could
be re-exposed to diffuse light, to give “these fi rst and
weak impressions just that addition which is necessary
to let the developer get hold of them, and carry them
forward to a visible impression.” Blair was aware thatINTENSIFYING
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