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If
you do much historical research, one of the things you're going to
run across is beautiful, highly-detailed panoramic drawings done in
the 17th, 18th, and the first half of the 19th Centuries. Many of
these drawings were done by the United States Army Corps of Topographical
Engineers- the Army's mapmakers. In a recently-published book on Western
Texas, several of these panoramic drawings were included. The text
stated that the technique for making such drawings is 'lost,' and
"no one today knows how the perspective was achieved."
The technique, which is very old--Leonardo da Vinci used it, as did
most of the 'old masters' who painted landscapes--hasn't been lost.
It's just been replaced, and most artists would be glad it's no longer
used. The technique required a very cumbersome piece of equipment
and, except in the dead of winter, the heat involved was terrific.
Still, the technique is well-documented. It's called camera obscura.
Almost as soon as the first explorers began to move into the west,
artists followed. Many of these artists were Army Topographical Engineers.
Their job was not to 'interpret' the scenery, but to render, as precisely
as they could, exactly what they saw. These were terrain drawings,
and they had to be as exact and detailed as possible, with proper
perspective. Looking at these drawings is almost like looking at photographs-and
that, almost, is what they are.
If you were a Boy Scout back in the '50s and tried for the Photography
merit badge, one of the things you had to make to get the badge was
a pinhole camera. A pinhole camera is the simplest camera there is-a
camera without a lens. To make mine, I found, in a second-hand store,
an old Kodak box camera that used the now-discontinued 616 film. I
removed the lens and shutter mechanism and replaced the lens with
a thin piece of sheet brass in which I made a very tiny hole. The
merit badge manual recommended the hole be .075" or 75/1000 of an
inch in diameter, but I didn't have anything to measure it with, so
I poked a dimple in it with the point of a dissecting needle and a
tackhammer and then filed the dimple off. I covered the hole with
a piece of electrician's tape. I loaded the camera, and when I was
ready to take a picture I simply removed the tape. A little experimentation
gave me the proper exposure time.
I had, in effect, made a miniature camera obscura. The word
camera actually means 'room' in Latin and obscura means
'dark.' That's exactly what the Topographical Engineers toted all
over the west in the 1830s, '40s, and '50s. It was a portable dark
room-not a 'darkroom' as in photography, but a dark room that could
be disassembled, loaded on wagons, taken to the point at which the
drawing was to be made, and then assembled for use. This 'dark room'
was a light-tight box about eight feet on a side. In the exact center
of one wall there was a small hole, usually equipped with an iris
that could be opened and shut from the inside.
The artist set up his box with the hole in the side pointing toward
whatever he was supposed to draw. He put, on the back wall, a very
large piece of drawing paper-about 6'x6'. If it was at all hot he
stripped to his underwear or even to the altogether, climbed into
the box, and his assistants shut the back to seal out all light except
that coming through the tiny hole. The light coming through that hole
projected, on the paper on the back wall, an inverted image of the
scene outside.
After considerable yelling through the lens-hole and shifting the
box, the artist got the scene he wanted on his paper. Then, with charcoal
sticks or pencils or whatever, he blocked in the major outlines of
the scene. That done, he banged on the box to be let out, probably
collapsed on the ground as soon as he got out, slugged down about
a gallon of water, and then rolled up his paper.
Once he had the paper back in the studio he transferred the huge image,
which was just outlines, to a smaller, more manageable piece of paper-or
canvas, if this was to be a painting and not a terrain drawing-by
means of an artist's pantograph. When the transfer was complete the
artist added shading and detailing, and a wonderfully accurate, seemingly
impossible drawing or painting emerged.
The
technique was in use by artists and engineers for nearly 500 years,
but in 1837 a Frenchman named Louis DaGuerre began to make it obsolete.
DaGuerre invented the first practical photographic process that year
and began to go public with it in 1839. At first this new 'art form'
was used mainly in studios, with only an occasional foray into the
outdoors. The emulsions DaGuerre used were very insensitive. Modern
photographers consider a film with an ASA or ISO speed of 25 to be
a very 'slow' film. DaGuerre's 'film speed' was probably around ASA/ISO
.0005. It took an exposure of as much as a minute and a half to take
a portrait in a brightly-lighted studio in 1840.
By 1847 photography was sufficiently advanced that a photographer
traveling with General Winfield Scott's Army in Mexico City photographed
Scott and his officers in front of several landmarks in the city.
In 1848 Mary Maverick, in her diary, mentioned having her photograph
taken in San Antonio.
By 1860 photography had advanced sufficiently that a huge camera with
a very long focal length, using a very large sheet of sensitized glass
or metal, could be transported by wagon fairly easily. Suddenly there
was no further use for the camera obscura and the pantograph.
An artist or engineer could capture, in only a few seconds, on the
photographic plate, in much more precise detail, what his predecessor
had labored for hours to capture on the paper on the back wall of
the sweatbox.
The camera obscura produced some of the finest art and engineering
drawings in the world. It was an invaluable tool, not merely for the
artists for whom it was designed, but for soldiers, cartographers,
and military engineers the world over. It's very doubtful, though,
that any of them lamented the demise of the old sweatbox when photography
replaced it.
© C. F.
Eckhardt
"Charley Eckhardt's Texas"
December 1 , 2007 column
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