Photography Arrives: Fixing an Image With Light

The daguerreotype, announced in 1839, worked by chemistry, not skill. A copper plate coated in polished silver was exposed to iodine fumes, which made the surface light-sensitive. Inside a camera, light from the scene struck that surface for minutes at a stretch, the subject sitting frozen the whole time. The faint image was then developed by exposing the plate to mercury vapor, which bonded to the exposed silver and brought out detail, and finally fixed with a salt solution so it would not keep darkening in light. The result was sharp, exact, and endlessly repeatable in a way no portrait painter could match.

Photography also caught what the eye could not. Eadweard Muybridge set up a row of cameras with tripwires along a track and photographed a galloping horse in 1878, producing twelve sequential frames of its stride. Laid out in order, those plates showed something painters had always guessed wrong: all four hooves leave the ground at once, but only when tucked beneath the body, not splayed out as centuries of horse paintings had shown. The camera corrected the human eye.

That double shock, exact likeness and exact motion, changed what painting was for. If a machine could copy a face or a gait better than a hand, painters had no reason to keep competing on accuracy. Many turned instead toward color, visible brushwork, distorted form, and subjective feeling, territory a camera could not touch, setting up the move toward Impressionism and the abstraction that follows later in the unit.