For a Vineyard kid, “when you first move away, there are two places: on-Island and off-Island,” said Kelley Callahan, viewing the exhibition by Marshall Pratt at the Periwinkle Gallery in Oak Bluffs which opened last weekend. In the show, A Vineyard Boy in Boston, Pratt uses photographs to depict this contrast, for instance by juxtaposing the image of a rock at Squibnocket and a similar rock in a Boston slum.

Mr. Pratt, 20 years old, was born and raised on the Vineyard. He is entering his junior year at the School of the Museum of Fine Arts in Boston. He is self-deprecating as he explains his decision to go to study art: “I knew from the beginning of high school that I wasn’t going to regular college — and I wasn’t all that good at music.”

But Periwinkle owner Judith Drew Schubert testifies to his talent: “Marshall can look at an old junk car or an abandoned power plant and see the beauty and capture it.”

Mr. Pratt had his first show, called Forgotten Post Cards, the Other Side of Martha Vineyard, at the Featherstone Gallery when he was a senior at the regional high school. Ms. Schubert came, loved the work and offered Mr. Pratt a show in her space back in 2006. The photographer visited with the gallery owner this spring and proposed the current exhibit, including his photographs of Boston.

In this exhibition, Mr. Pratt’s photos in the gallery are displayed in a variety of settings: mounted on record albums, on spray-painted cardboard, book covers, and even the lower hatch of a VW Bus. “We decided together that the classic black gallery frame and white matte were dead for me. They didn’t represent how my photographs should be seen,” he said. “Judith gave me freedom, and we worked out what you see.”

Images that are not mounted on miscellaneous objects are hung on the wall by bulldog clips suspended on nails. According to Mr. Pratt, this display lends an informality that accords well with the urban decay many of the photographs illustrate.

Mr. Pratt’s largest photographs can be almost four-and-a-half feet long. The photographer explained that he develops these images “in makeshift fashion,” projecting from nine feet high onto photo-sensitive paper that is rolled out on the floor. The exposures can take as long as five minutes. Two people are then needed to scroll the long sheets through a trough of chemical. The paper is then hung by clothespins to dry.

“It’s hard for me let those photos go,” Mr. Pratt said, speaking of selling his work, “because I’ve had to baby them so much.”

Mr. Pratt’s travels have brought him outside Massachusetts. A large picture of a street front church emblazoned with the message “God is love” is clearly from New Orleans. In his artist’s statement, the photographer writes, “I chose not to title the works on the wall because I wanted the viewer to make up his or her mind concerning what they see. The locations and titles are listed on the price sheet under the corresponding number, but it was important to me that the pieces be seen before the titles.”

According to Mr. Pratt, a theme of the show is the re-discovery of what constitutes an island. He explains that even the images of distant cities can have an island feel, if they document places to which people “are bound, economically, physically, mentally.” Mr. Pratt sees a dynamic quality in the exhibit, so that viewers can see how islands “are constantly drifting farther off shore.”

As an example, he points to a series of photographs of a convenience store in Boston where he went daily to buy hot pastrami sandwiches. As he became friendly with the owner, Mr. Pratt became aware of the isolation and sense of belonging in the man’s life. While the artist was aware of his distance from the Vineyard, he also found “an island feel” in the city.