Sometimes the march of technology is benevolent. Sometimes, not so much.

The National Portrait Gallery exhibit Antebellum Portraits by Mathew Brady imparts this lesson, again.

The small exhibit focuses on the early, pre-Civil War portrait work by Brady, arguably the most famous American photographer of his day. In 1844, Brady opened a New York City gallery to show his daguerreotypes, just five years after the development of the first commercially viable technique for making photographs. Brady’s daguerreotypes, which account for about half the works in the exhibit, are impressive, particularly the ones made in larger sizes.

An 1845 portrait Thomas Cole shows the renowned painter’s well-lit face in contrast to his impenetrably black garb. And the 1852 portrait of former President Martin Van Buren—a relatively late example before the daguerreotype fell out of favor as a photographic method—is a joy, clearly showing defined wrinkles and the texture of his jacket lapel. (History nerd alert: The exhibit surfaces an 1848 portrait of Dolley Madison, enabling curators to bridge a long sweep of American history via the daguerreotype, from the spouse of a founding father to Abraham Lincoln.)

The second half of the exhibit—after Brady successfully surfed the technological change roiling the photographic arts — is less striking.Brady, and many other portraitists, shifted to the ambrotype in the mid-1850s. The ambrotype process offered the benefit of producing multiple prints from a single glass negative, and Brady’s ambrotypes have a pleasant cream-hued white and a strong range of shades of light and dark.

On the other hand, the extreme detail and the shimmering metallic etching of the daguerreotype is lost in the process, even at the largest plate sizes.|

Lincoln’s place in the exhibit revolves around a print Brady made using a large-format glass negative. It’s historically important — but less for its artistry than because countless copies were made and because leading media outlets of the time, including Harper’s Weekly, translated his portrait into a cross-hatched drawing that spread his image far and wide in print. In the end, technological change may have had a questionable impact on art, but it did wonders for Lincoln — and for Brady.

Through June 3, 2018 at the National Portrait Gallery, 8th and F Streets, NW, Washington, D.C. Daily, 11:30-7:00.