Over the last several years, the Mildred Lane Kemper Art Museum has built an exceptional collection of works by an international array of contemporary artists who both examine and expand the parameters of traditional photography. For these artists, photography is not a single, rigidly defined discipline or practice, but a versatile medium that can be filtered through a wide range of artistic processes and used to address a wide range of aesthetic questions and concerns.

Next month, the Kemper Art Museum will showcase this collection in Focus on Photography: Recent Acquisitions. Organized by assistant curator Karen Butler, the exhibition will feature more than 100 pieces by more than 20 artists, ranging from historical figures who helped define early photographic standards to contemporary photographers working within what art historian George Baker has termed "photography's expanded field." Taken together, these artists offer a lens through which to address the question: What is photography today?

The earliest works on view are rooted in photography's documentary tradition. Edward Curtis sought to record and preserve the culture of disappearing Native American tribes, yet he also was deeply influenced by aesthetic conventions — the portrait, the pastoral landscape — borrowed from traditions of painting. This dichotomy reflects the complex nature of early 20th-century photography, which frequently negotiated between scientific instrument and artistic endeavor. Conversely, in artfully staged portraits such as Picasso, Cannes (1955), Lucien Clergue consciously attempted to supplant the painted portrait with a photographic image capturing the individual's psychological essence.

The work of artists such as Andy Warhol and Louise Lawler would further transform our understanding of the photographic image, radically undermining its apparent promise of objective knowledge or truth. Warhol, who lived life both through and for the camera, is represented by a large group of working Polaroids and black-and-white snapshots, the latter of which portray personal and public activities but, paradoxically, reveal very little about Warhol himself. Lawler, meanwhile, is represented by Not Yet Titled (2004/05), a recent example from a long line of photographs that investigate the life of artworks after they leave the studio and enter the public domain.

These figures set the stage for a vast array of artists whose varied forms of critical engagement define the state of photography today. In Ecrivain public / Public letter writer, Rafaèle Decarpigny (2007), Sophie Calle uses photography to explore questions of subjectivity and identity, creating an unconventional portrait out of the response of one woman, a professional letter writer, to an upsetting email that Calle received from a boyfriend. Questions of identity also inform Christian Jankowski's series Poster Sale (2005), which depicts 40 Washington University students posing with images they had selected to decorate their dorm rooms, thus allowing viewers to glimpse the ways popular culture contributes to the construction of individuality.

In Untitled (Pollock/Titian) #4 (1984/2005), Andrea Fraser deploys photography as a form of institutional critique by juxtaposing and then re-photographing slides of well-known paintings by two renowned male artists. Wolfgang Tillmans, in Wald (Briol II) (2008), addresses the issue of photographic representation head-on by photocopying his own photograph, of a man walking through a forest, rendering it dark, flat and blurry. Tillmans then scanned, enlarged and printed the photocopy again, this time as a singular image, thus placing it somewhere between a photograph and a unique artwork.

Rounding out the exhibition will be recently acquired works by Howard French, David Goldblatt, Doug Hall, Ulrike Kuschel, Sharon Lockhart, Alen MacWeeney, Abelardo Morell, Simon Nieweg, Georges Rousse, Georgina Starr, and John Stezaker.