Leading ladies

CAMBRIDGE -- The power of photography both to bestow celebrity and mock it inspires ''Girls on Film," a sly, cheerfully unsettling exhibition put together by Julie Buck and Karin Segal at Harvard's Carpenter Center for the Visual Arts. It runs through Sept. 18.

The show draws its material from a technological footnote to Hollywood history. Since feature films consist of multiple reels, each reel must have a consistent color balance or (with black-and-white films) tonal density. Today, color balancing is done digitally. But from the 1920s until the 1990s, processing-lab technicians would splice ''color-timing test strips" onto the beginning of each reel. A woman's coloration was said to provide a particularly good tonal gauge, so it became customary to have female studio employees -- aspiring actresses, secretaries, telephone operators, whoever -- pose with the control strips. They were called, for reasons unknown, China Girls (did David Bowie know about this?).

It's hard to think of a better -- or more melancholy -- example of how photography lies (in both senses of the word) along the fault line of anonymity and identity. These women are like a Popular Mechanics version of pin-ups. Each is ready for her close-up, Mr. DeMille. Each even gets it -- but with close-ups like these, who needs a cutting-room floor? These women are nameless and effectively faceless. The only thing that matters, after all, is their skin tone, with the occasional come-hither pose thrown in for the boys back in the lab. ''Girls on Film" can hardly be improved upon as a metaphor for Hollywood's treatment of women.

Buck and Segal, who are conservators at the Harvard Film Archive, retrieved the 70 images here from discarded film stock. In assembling the show, they've operated more as artists than curators. They've worked over the images in various ways. Some have been digitally restored. In a number of them, the color bars have been eliminated, and in others they've been made larger. Buck and Segal have substituted Barbie dolls for two of the China Girls. According to the show's press material, they've also included themselves in two images, though as the exhibition has no labels, it's impossible to say which ones. Their anonymity might be seen as a show of solidarity with their fellow sitters.

''Girls on Film" is perhaps best understood as a single work -- an installation, a disassembled mosaic. The images run along the gallery walls in a single strip -- a film strip, as it were. Reinforcing this effect, all have been blown up to a single size, 12 inches by 15 inches.

Uniform dimensions and uniform function do not mean uniform content. Some women smile, some are blank-faced. Some stare back at the camera, some look away. The one clue to chronology is hairstyles, which vary considerably (coiffure as carbon dating!).

Buck and Segal have arranged things so that poses intermittently chime and clash. It's amazing how many variations there are on the tilt of a human head. The size of each face relative to the space varies, which imparts a vague sense of claustrophobia, as if the woman is trapped in the frame (film cel as isolation cell?).

Inevitably, a viewer begins to discern, or fill in, biographical details. That second woman on the first wall must have been told again and again that she looked like Dietrich. How long before she came to hate it? The next-to-last woman on the fourth wall could be Cameron Diaz's sister. That first woman on the back wall, with the white fur and diamond brooch? Surely she's French -- no, not just French, Parisian. The image could be from a screen test for ''The Rules of the Game."

The color technicians wanted to enhance the test strips with the presence of these women. So, too, do we want to enhance their images with some sense of who they were, what lives they led. That we'll never be able to do so is made all the more poignant by the fact that the process that has led to their simulacrum of screen immortality is no more.

''The very digital technology that allowed us to recover and rework these images -- elevating them to the status of icons or portraits -- has also made them all but disappear from the film industry," Segal notes. Well, Norma Desmond never did get that final close-up, and Mr. DeMille's dead now, anyway.

Mark Feeney can be reached at mfeeney@globe.com.