His earliest daguerreotype is dated 1840.

Some of the earliest daguerreotypes, in the mid-1800's, were pornographic.

Between 1842 and 1843 he traveled to Senegal, Guadeloupe and India, where he took a number of early daguerreotypes.

In addition, the earliest daguerreotypes had exposure times ranging from three to fifteen minutes, making them somewhat impractical for portraiture.

At the time the process was introduced, daguerreotyping a brightly sunlit subject typically required about ten minutes of exposure in the camera, so the earliest daguerreotypes were of still lifes and landscapes.

Manuscripts and rare early daguerreotypes and portraits are also exhibited there.

The museum's current 300-piece show, "Developing Greatness: The Origins of American Photography, 1839-1885," features early daguerreotypes, notable portraits and Civil War photos (through 2007).

From the earliest daguerreotypes into the 1960's, the pictures paid homage to the notion of childhood innocence.

But the best early daguerreotypes, like Choiselat's view across the Seine, remain weirdly unlike any other photographs, with their own mysterious, ethereal space.

The early daguerreotypes, which required extended moments of stillness to be produced, are artificially posed, beginning a tradition of stiff photographic portraiture.