In 1878, Jacob Riis, a police reporter for the New York Tribune, stepped out of his office and into the squalor of New York’s Mulberry Street. A few years earlier, he had found his calling. His Methodist minister had told him that “what the world needs is consecrated pens.” When police headquarters was calm, Riis wrote passionate articles about the tenements that were creeping from the industrial areas of Manhattan toward genteel neighborhoods on the island. But his voice was largely ignored.

It wasn’t until Riis embraced the new medium of his day that he was able to tell the story of his calling. His camera turned out to be as much a consecrated tool as his pen. Riis’s exploration of photography—not a technological end in itself, but as a way to illuminate his narratives—added visual drama to his already powerful written work. Understanding the technical limitations he faced and the ethical boundaries he crossed can help today’s journalists navigate through this media age without losing their souls.

Riis enthusiastically tinkered with new technologies. He started by taking photographs with the slow, inconvenient wet-plate negative and quickly adopted the faster, dry-plate method when it became available. Riis was one of the first in America to use Blitzlichtpulver fired from a pistol to create the earliest flash photos. The high-contrast images accentuated the grittiness of the five-cent hotels of the Lower East Side and caught the alley he called “Bandit’s Roost” off guard.

Newspapers were not ready to print his stark images. Halftone printing was still rare and expensive. The early editions of his classic book, How the Other Half Lives, contained illustrations of his photos, not the pictures themselves. His audience had to attend his lectures at evangelical churches to see his photos projected on a screen with a device so unusual it was dubbed a “magic lantern.” This multimodal delivery of images and words reached an audience in a fresh, memorable way.

Riis’s photos took middle-class New Yorkers on a harrowing journey into an exotic locale that was a part of their own city and yet largely unknown to them. “In viewing those prints, I find myself identified with the people photographed. I am walking in their alleys, standing in their rooms and sheds and workshops,” Ansel Adams wrote in the foreword to a biography of Riis. Like Adams, Riis took photos the hard way—in the field, not the studio. Perhaps this is a lesson for today’s journalists: to think of technology as a way to expand and enhance the telling of stories rather than a way to make storytelling more convenient for themselves.

In his autobiography and in How the Other Half Lives, Riis reveals the ethical choices he made to capture those images. Riis admits to paying children with cigarettes to get them to pose as lazy “Street Arabs” sleeping under an apartment stoop. He threatened a landlord with a complaint to the authorities to gain access to shoot an illegal hotel. The resulting photo is “Five Cents a Spot,” one of the most famous images of Riis’s collection.

As a new media pioneer, Riis was one of the first journalists to understand the visceral reaction that images can provoke. At the same time, when Riis, originally from Denmark, describes ethnic populations in New York, he appears to be a self-hating immigrant. In his words and images, he employed what are seen today as stereotypes that confirmed middle-class prejudices of the poor, leaving little room to consider a diversity of perspectives. He simplistically concluded that the cramped alleyways that he photographed were the cause of poverty and criminal behavior. So Riis showed audiences images of the open scenery of his native Denmark to justify why he was more industrious and ambitious than other New York immigrants.

Paul Niwa teaches online journalism as an assistant professor at Emerson College in Boston.