First
Practical
Photographic
Process
Announced
170 Years
Ago
2009 marks
the 170th
anniversary
of the birth
of
photography.
In 1839,
Louis-Jaques-Mande
Daguerre
released to
the public
complete and
detailed
instructions
on his
photographic
imaging
process,
commonly
known as
the daguerreotype.
Daguerre
developed
the process
beginning in
the early
1830s in an
effort to
capture an
image using
chemistry
and a
camera-obscura.
He
discovered
iodine
crystals
could etch a
copper plate
that had
been coated
with silver
sensitive to
light. The
problem was
that the
exposure
time was so
long the
process was
largely
impractical
until two
discoveries
allowed for
a dramatic
reduction in
exposure
time. The
first was
the
discovery
that mercury
vapor
rapidly
developed an
image on a
plate that
had only
been exposed
for 20-30
minutes,
instead of
the many
hours
required
before. The
second
development
was the use
of bromine
as a way of
greatly
enhancing
the
sensitivity
of the
plate,
reducing
exposure
times to
around 3
minutes.
Once his
method was
perfected,
Daguerre
presented
his findings
to the
French
Academy of
Sciences in
1839,
agreeing to
make the
process free
to the
public,
although the
government
did grant
him a
comfortable
pension for
the rest of
his life in
exchange for
his
publication
of the
process.
Daguerreotypes
are a direct
positive
print,
meaning
there is no
intermediate
negative.
This makes
each
daguerreotype
unique in
the world,
although
cameras were
developed
that could
make
multiple
images of
the same
subject by
using
multiple
lenses.
However
even with
those
images,
there are
very subtle
differences
due to the
position of
the lenses
on the
camera body.
Daguerreotypes
did have
several
notable
drawbacks.
The first
was that
since the
surface is a
highly
polished
mirror there
is a very
limited
angle at
which the
image is
visible.
Another was
since the
developing
process
involved
mercury
vapor, many
of the
people
working with
the images
suffered
mercury
poisoning.
Additionally,
although the
plates were
quite
sturdy, the
images were
very easily
scratched,
which is why
surviving
daguerreotypes
today are
always
encased in
glass, and
many were
tinted with
a gold
chloride
solution to
help harden
the image,
giving them
the distinct
sepia tones
of many old
photographs.
Despite
these
limits,
daguerreotypes
are among
the most
beautiful
examples of
photography
in the
world,
offering
both a
tremendous
range of
tones and
virtually
limitless
detail.
Images
observed
under a
magnifying
glass or
jeweler's
loupe show
rich details
such as
fabric
texture,
brickwork in
distant
buildings,
and even
minute
facial
details such
as eyelashes
and irises.
The process
remained
popular into
the early
1860s, when
other
developments
such as
wet-plate
images
gained in
popularity.
For over a
century
daguerreotyping
was
essentially
a lost art,
but in
recent years
there has
been a
resurgence
of interest
in the
technique,
and there
are several
daguerreotype
artists
active in
America
today.
Examples of
early
daguerreotypes
can be found
in various
museums and
historical
sites,
including
Miramont
Castle, and
collectors
can find
items for
sale on eBay
for prices
ranging from
$20 -
$5,000+
depending on
the size and
nature of
the image.
Also, the
Pikes Peak
Library
District has
a facsimile
of the
original
English
translation
of
Daugerre's
publication
available
for
checkout.
