The nature of photography – as a science, a mode of communication, as an artistic medium – is at the center of many discussions about the history of art.

It’s relatively replicable nature along with its technological implications raises questions about how we constitute artmaking and what we consider art, from early daguerreotypes, an early type of photograph, to Instagram posts.

The exhibit, “In the Light of the Past,” which is on display at the National Gallery, showcases the works collected in the 25 years since the NGA began actively collecting photography.

In 1949, artist Georgia O’Keefe and the estate of Alfred Stieglitz donated the “key set” of Stieglitz’s photographs, according to a news release.

Later, the NGA received photographic works by Ansel Adams and Walker Evans en masse. In 1990, the gallery founded its department of photographs and has been actively collecting the medium for 25 years.

The exhibition, co-curated by Sarah Greenough,current head of the photography department, and Diane Waggoner, features 175 works spanning from the earliest forms of photographs to some of the most current work in the medium.

In Light of The Past

Early photographers experimented with photography in its true form. Early wall text asks, “Was photography best understood as an art or a science?”

“What subjects should photographs depict, which purpose should they serve, and what should they look like?” the text said.

Some are sharp – the recognizably deliberate, contrast-heavy contours of albumen prints – from the patterns of a decorative vase to the reflection on a grape to the curves of a woman’s bottom.

Other works are not as crisp. Some deliberately, as in the case of 1860s British works, others are simply consequences of the medium, as with daguerreotypes, an early type of photograph printed on a metal plate.

The early urban scenes are startlingly empty – from early views of central Paris to the train station at Toulon. The reasoning for this is twofold. First, some of the photos were meticulously staged and prepared to be empty. Second, early cameras could not capture images of fast-moving human beings. In Gustav Le Gray’s “The Pont Du Carrousel, Paris…,” shadowy forms of moving humans are just barely visible.

The early landscape photos of an ever-expanding American West show artists on three frontiers: artistic, geographic and technical. Platt Babbitt’s ambrotype “Niagara Falls” presents a photographic angle on the natural wonder painted in Frederic Edwin Church’s enormous landscape “Niagara,”a painting on view at the NGA until very recently as part of “American Masterworks at the Corcoran.”

At this point historically, American artists led by Stieglitz strove to establish photography as a fine art. One such example, Frederick Evans’s exquisite “York Master, North Transept…” was on view at the NGA last year as part of “A Subtle Beauty: Platinum Photographs from the Collection.” It is surely worth of the double limelight.

Edward Steichen’s “Rodin” truly blends photography and fine art. It is a portrait of the great French sculptor famous for “The Thinker” and more.

Eventually, modernity begins to creep through: there’s Georgia O’Keefe’s thimbled fingers; there’s an American cityscape; there’s a snowy gaslit park; there’s what appears to be the Queensboro Bridge. There’s the famous gelatin silver print of a mill girl child laborer in a North Pownall, Vt., cotton mill captured by sociologist-turned-photographer Lewis Hine.

The  Fort Peck Dam by Margaret Bourke-White was immortalized on the front cover of Life Magazine’s very first issue on Nov. 23, 1936. The photo represents another convergence between photography and journalism.

The photos of the Eiffel Tower and Berlin’s Radio Tower are geometric and modern. An untitled work by Marianne Brandt blends the avant-garde with the dated. The smoke of a city, a chained-up businessman, a seductive 1920s flapper, the plain dignity of a female factory worker, the contrails of formation-flying biplanes, a high tension power line and a pair of floating zeppelins combine in a cacophonous collage that, in totality, is coming out of a man’s lit puffing cigar. The wall of visual information perplexes and excites.

A circa 1938 work by György Kepes shows a face overlaid with a peacock feather on one eye and a red gouache leaf skeleton on the other.

Walker Evans, chronicler of the Great Depression, captures pure Americana in a photo of overlapping Beaufort, S.C., signs announcing “Art School,” “Fish Co.,” “Public Stenographer” and “General Lafayette Spoke From This Porch – 1824.”

In the postwar era, extravagance takes the cake – fancy dresses, jewelry, tiaras, lit up boulevards and expensive children’s toys. Robert Frank’s 1955 photo “Trolley – New Orleans” illustrates America’s racial divide: a small white child is holding his hand to the small wooden bar, installed on a seatback with brass pegs, that separated the white riders’ section from the section for people of color.

When the medium became more accessible, the composition and subject became the focus. In Irving Penn’s “Ballet Society, New York…,” a trio of stern-faced men sit on the ground in suits as a dazzling young woman clad in a sheer, draped grey toga and silk-leaf crown stands at the rear of a right-angle room corner starting back at visitors.

In the most modern works, the works often trick the eyes. Mel Bochner’s “Convex Perspective” creates the jarring optical illusion in which fuzzy grey dots appear at the juncture of black square forms on a white field.

“In Light of the Past: Celebrating 25 Years of Photography at the National Gallery of Art” runs until July 26.

Evan Berkowitz is a freshman journalism major and can be reached at evanjberkowitz@gmail.com.