Periodically, small, modest shows have the impact of blockbusters. The art on view offers countless pleasures, enough to merit standing in line or traveling long distances; and the catalogue in some way sheds new light on the subject at hand, by reinterpreting long held assumptions or filling in gaps of what is known. More and more, exhibitions at the Sterling and Francine Clark Art Institute in Williamstown, Mass., fit this bill.

Many people are still talking about summer programs at the Clark featuring exhibitions of landscapes by Gustav Klimt, "Renoir in Algeria," and pastels by Jean Francois Millet. Now, the museum boasts "douard Baldus: Landscape and Leisure in Early French Photography," a show that should not be missed.

Although the Metropolitan Museum of Art mounted a superb retrospective of Baldus' salted paper and albumen prints almost ten years ago, the French photographer, active during the 1850s, is not yet a household name. This lovely, elegant show should enhance his reputation further besides setting him in the context of such contemporaries as Nadar, Gustave Le Gray, Charles Marville and Camille Silvy, among others. Most of the prints hanging in the special exhibition galleries are owned by the Clark, which has been on a buying spree since 1998 -- what director Michael Conforti calls an "ongoing initiative to build a collection of early photographs"-- and the Troob Family Foundation, which keeps its holdings on deposit at the Clark.

If you're interested in the history of photography, life in mid-19th century France, public as well as private patronage issues, or just enjoy a good, scholarly detective story, you should spend a day in the country looking at views of a day in the country taken in 1856, not quite 150 years ago, and 36 related works shot out-of-doors.

The nine core prints in the show were taken at the Chateau de La Faloise, a residence in various incarnations since the early 14th century. At the time of Baldus' visit, Frederic de Mercey, "a forgotten public figure," as curator James A. Ganz puts it, his English wife, and their twin sons used the chateau, last renovated in 1827, and its manicured grounds as a country estate. Fourteen miles south of Amiens, it was a two-hour train ride from Paris, where de Mercey, director of the Office of Public Works, lived with his family across from the church of the Madeleine.

Quoting Malcolm Daniel's important Metropolitan Museum monograph of 1994, Ganz emphasizes that these prints are neither portraits of the owners nor the chateau they inhabit. Rather, in keeping with the soft, painterly focus of salt prints, these images are, as Daniel observes, "a rare foray into the depiction of plain-air leisure." You will doubtlessly agree with this suggestion as you regard the nine views with looking glasses provided in the room where they are displayed separately from the rest of the show.

In several instances, as Ganz points out, behatted seated and standing men function as "'staffage' figure[s] merely intended to enliven the scene and contribute to its sense of repose." Inspector Poirot himself would applaud Ganz's unraveling of the mise en scene, identifying the times of day when the individual pictures were recorded and where they were taken on the grounds.

f timing is everything, consider this: the year before Baldus made and printed these images in a day spent at the Chateau de La Faloise, "French photographers," according to Ganz, "embarked on an intense four-year campaign to elevate the status of photography from an industrial marvel to an art form." In late 1856 or early 1857, the Societe franaise de photographie held its annual exhibition in the studios of Gustave Le Gray and the Bisson brothers, 17 years before Nadar, the latest tenant, lent these quarters to the first Impressionist exhibition.

The accomplishments of these wondrous pioneers are borne out in many of the other prints on view at the Clark. These range from Count Olympe Aguado's image of a tree in the Bois de Boulogne (1856) to Le Gray's The Breaking Wave, Sete (1857) to Nadar's Skull-lined Walls in the Catacombs of Paris (1862).

In the process of calling attention to Baldus's renderings of the Chateau de La Faloise, Ganz has shed light on de Mercey as well. He has discovered that it was the aristocrat's offices -- he was a member of the Historic Monuments Commission and worked for the Administration of Fine Arts -- which sent Baldus to document architectural monuments in the Midi (1853), the construction of the Louvre (1854), the floods of Lyon and Avignon (1856) and the Imperial visit to Normandy (1858). And de Mercey was instrumental in commissioning some of the most glorious mid-century in Paris: Delacroix's ceilings and side walls for the Palais du Luxembourg, Palais Bourbon, the Galerie d'Apollon in the Louvre, and a chapel at Saint-Sulpice.

De Mercey was himself a painter who exhibited in the annual Salons. No less a personage than art critic Charles Blanc, said upon his friend's death in 1860, "There wasn't an artist's studio in Paris that he hadn't visited, not an exhibition that he didn't know by heart, not a quality that he hadn't tested."

"douard Baldus: Landscape and Leisure in Early French Photography" not only provides a fuller picture of a great cameraman's achievements and those of his contemporaries, it also calls attention to an aristocratic painter and adminstrator who played an important role in the artistic life of his time.