Is there such a thing as a history of photography, and if so, of what does it consist?

For a variety of reasons, the answer to that question is not as obvious as it first may seem. And it is at the center of an intriguing pair of new photography exhibitions that open today at the Baltimore Museum of Art, Parallel Tracks: The History of Photography in Two Brief Installments and Common/Places: Contemporary Photography From Germany and Northern Europe.

Parallel Tracks is a mostly chronological celebration of the museum's extensive collection of 19th- and 20th-century vintage prints by acknowledged masters of the medium.

Instead of hanging the photographs on the wall gallery-style, however, curator Darsie Alexander has simply set the approximately two dozen framed and matted prints on a shoulder-level railing that runs around the room, so that the pictures are crowded together like family snapshots sitting on a mantelpiece. The effect is to lend these well-known images an easy informality and intimacy with viewers that belie their often iconic status.

Half the show focuses on the development of what is known as "street" photography - pictures of people in public places going about their business - and features works by Eugene Atget, Andre Kertesz, Brassai, Diane Arbus, Robert Frank, Gary Winogrand and others.

The other "parallel track" of the show's title deals with studio photography, a vast and rather amorphous field that takes in everything from pictorialists like Baron Adolf de Meyer to "straight" photographers like Edward Weston and Imogen Cunningham, plus surrealists like Man Ray and Rene Magritte and postmodernists like Cindy Sherman and Laurie Simmons thrown in for good measure.

If the inclusiveness of that latter list seems to veer perilously toward incoherence, however, perhaps the fault can't be laid entirely at the curator's feet. One of the show's avowed purposes, after all, is to offer visitors an opportunity to see many fine vintage prints - photographs printed by the artist at the time the images were originally made - that otherwise are rarely seen by the public.

Rather, the apparent confusion in lumping so many kinds of photography together seems to stem from a crisis in the discipline of photographic history itself.

Consider that for most of the 20th century (and the 19th as well), the history of photography was considered to be synonymous with the history of its technical development - from daguerreotype to wet plate to positive-negative processes and so on right down to the digital revolution.

The definitive American expression of photographic history as technical evolution was established in the 1930s by Beaumont Newhall and his wife, Nancy, in their seminal History of Photography, which became the standard text for the next two generations of photographic historians and the conventional wisdom of working photographers down to the present day.

Yet by defining photographic history narrowly in terms of the development of its technical processes, the Newhalls artificially (and doubtless inadvertently) limited photography's connection to the broader field of art history in general.

No one, for example, would try to write a history of painting based solely on technique - fresco, oil paint, watercolor, acrylic, etc. On the contrary, the history of painting has long been recognized as the history of styles - e.g. from renaissance and baroque to neoclassicism, romanticism, modernism, etc.

Thus the interpretation of photographic history as the evolution of its technical development has left photography the odd man out in the eternal debate over whether camera images are art or something else. Meanwhile, the opposition between style and technique has led some art historians to question whether the history of photography even deserves recognition as a separate field of inquiry.

A more analytical approach to the problem might have been to look at different styles within the two broad categories of "street" and "studio" photography.

Stylistically, Kertesz's bird's-eye-view street scenes, for example, or Weegee's deadpan tabloid photos of gangsters are both quite different from Winogrand's fish-eyed snapshots of Manhattan pedestrians. Yet photographic historians still have not developed a workable stylistic vocabulary to account for these differences.

Common/Places, the second show in the BMA exhibition, suggests a strategy for overcoming these difficulties. While the show nominally groups its photographers - Bernd and Hilla Becher, Thomas Florschuetz, Candida Hofer, Sabine Hornig, Rineke Dijkstra, Thomas Ruff and Gerhard Richter - together on the basis of geographic proximity, these artists also share deep stylistic and philosophical affinities that could serve as the basis for a much broader reinterpretation of the discipline of photographic history.

As Alexander notes in the texts accompanying the exhibition, contemporary German and Northern European photographers exploit the ability of modern, large-format view cameras to precisely capture minute details that, when enlarged to monumental scale, transform their subjects from banal, commonplace objects and locales into bizarre and often otherworldly visual mysteries.

This is as true whether the subject be Dijkstra's awkward adolescents, Hornig's empty store windows or Ruff's blurry enlargements of newspaper photographs.

It is a style of coolly precise, close observation of the most ordinary people, places and things that was pioneered by the Bechers and which has evolved into a whole school of contemporary photography that draws its inspiration from American conceptualism and minimalism as well as from the tradition of encyclopedic description practiced by August Sander and other early 20th-century German photographers.

Both these shows, in short, offer plenty of food for thought, with the added bonus that the monumentally scaled color photographs of Dijkstra, Florschuetz and Hornig, in particular, are visual stunners.

Exhibit

What: Parallel Tracks and Common/Places

Where: Baltimore Museum of Art, 10 Art Museum Drive

When: Through May 25, Hours: Wednesday through Friday 11 a.m. to 5 p.m.; Saturday and Sunday 11 a.m. to 6 p.m.

Admission: $7 adults; $5 students and seniors, Call: 410-396-7100, or visit the museum Web site at www.artbma.org