DOCUMENTARY STYLES: Nan Goldin’s photograph “C.Z. and Max on the Beach, Truro, Massachusetts” (left) and Danny Lyon’s photograph “Tesca, Cartagena, Colom­bia” (right) are featured in concurrent exhibitions of the artists’ work. Photo © Nan Goldin, courtesy of the Museum of Modern Art. Photo © Danny Lyon, courtesy of Edwynn Houk Gallery, New York / Whitney Museum of American Art.

In her 1977 book On Photography, Susan Sontag argued that photography creates its own “ethics of seeing.” Sontag suggested that photography has created “the sense that we can hold the whole world in our heads—as an anthology of images.” This not only gives us visual information, but also expands our sense of what we have permission to observe and what is worth noticing. The use of camera technology, she observed, has democratized both the means of production and the variety of images produced.

The advent of social media makes Sontag’s thesis even more relevant. Every Instagram and Snapchat user adds to the profusion of images that saturate our lives and shape our sense of “real experience.” As the kids say, “Pics or it didn’t happen.” Artists engaged with photography must wrestle with the ethics of seeing that the medium demands.

Two photography exhibits in New York offer a case in point. While Sontag was meditating on the nature of the photographic image, artist Nan Goldin was taking the photographs that would become her major work, The Ballad of Sexual Depen­dency. This slideshow of 700 still images set to music is on view at the Museum of Modern Art through Feb­ruary 2017.

For over two decades Goldin photographed herself, her lovers, and her friends in the intimate corners of their lives: having sex, putting their kids to bed, shooting heroin, dancing at parties, and covering up the bruises of domestic abuse. The images are raw, often sexually explicit, difficult to view, and impossible to ignore. Goldin describes The Ballad as “the diary I let people read. . . . It allows me to obsessively record every detail. It enables me to remember.”

The connection to the hyperconfessional world of social media is not hard to draw. The New York Times ran an article in August with the tongue-in-cheek title, “Nan Goldin Wants You to Know She Didn’t Invent Instagram.” But they’re not the same. Goldin’s work requires that you confront other physical bodies, and the discomfort caused by the images removes polite distance between viewers. Checking an Instagram feed, on the other hand, is done alone on your phone.

But there are similarities too. While Goldin is more skilled with a camera, more intentional, and more unflinching in what she puts before her lens than the average Instagram amateur, she too is documenting the world in images, filtering those images with a particular intent and sharing them with friends and strangers.

The Whitney Museum of American Art in New York hosted the first retrospective of Danny Lyon’s work, Danny Lyon: Message to the Future. The exhibit closed on September 25 but will move to the Fine Arts Museums of San Francisco. Lyon works in a photo-documentary style and brings to mind giants of photo-realism like Walker Evans, Dorothea Lange, Ben Shahn, and Russell Lee.

He photographs prison inmates, Hell’s Angels bike gangs, and tattoo artists. The retrospective is beautiful and moving, full of humor, light, and pathos. You sense Lyon’s respect for diverse human life; his camera draws out the humanity of his subjects. But Lyon’s work is also cautious in a way that Goldin’s isn’t. He never reveals the dark, dangerous, or unseemly aspects of the lives he photographed. And he is not documenting his own life, but the lives of strangers.

We often criticize social media for its edited quality. Users edit out the messy realities and project a vision of the life they want others to think they have. 

Sontag thought that the democratization of experience was happening as more cameras appeared in more hands. This has only accelerated in the age of smartphones. Goldin’s and Lyon’s work re­minds us that the line between the artistic photographer offering a particular vision of the world and the Instagram amateurs documenting their life is not fixed. Both exhibits ask: When everyone is a photographer, what do the images mean?

A photographic image is always a paradox: it both reveals and yet edits reality. We feel that we are seeing something exactly as it is, but we are also aware that the image is manufactured. We should be neither so naive as to think that our images tell the unvarnished truth, nor so jaded as to miss the human qualities revealed in them. What we think is worth noticing shapes our perception of ourselves and our neighbors, now more than ever.

A version of this article appears in the October 12 print edition under the title “Outside the frame.”