Repeat photography. The art and science of recording a scene a second time

The present contains nothing more than the past . . . Henri Bergson Picture this: The year is 1873, and William Henry Jackson, photographer for a United States Geological Survey team, is peering into his ground glass at White House Mountain and Elk Lake. He exposes the plate, the result being a lovely landscape photograph.

Now jump ahead 104 years: The year is 1977, and Mark Klett and JoAnn Verburg, chief photographer and project coordinator, respectively, of the Rephotographic Survey Project, stand on the exact same spot. The mountain is now called Snowmass, and the body of water Geneva Lake, but it looks pretty much the same . They are there to replicate Jackson's image, nothing more and nothing less.

What Klett and Verburg specialize in is rephotography, or repeat photography, ``the practice of finding the site of a previous photograph, reoccupying the original camera position, and making a new photograph of the same scene'' (as defined in the ``Bibliography of Repeat Photography for Evaluating Landscape Change'' (University of Utah Press). This is easier said than done, but that has not stopped more and more people from rephotographing (usually though not always) landscapes, the better to understand not only physical, social, and other manner of change, but also time.

Just who is doing repeat photography is made clear in the ``Bibliography,'' which reveals that there are people studying such things as volcanic action, vegetation change, Sierra glacier variation, the mesquite problem in southern Arizona, the effects of fire on forest ecology, fault scarps, slope stability, and the rapid expansion or contraction of various towns.

What repeat photography provides scientists with is a now to go along with a then.

Certainly the most aesthetically conspicuous book to evolve from a repeat photography project is ``Second View: The Rephotographic Survey Project'' (University of New Mexico Press). Klett, Verburg, and photographers Rick Dingus and Gordon Bushaw rephoto-graphed scenes done by the likes of Jackson, J. K. Hillers, Timothy H. O'Sullivan, A. J. Russell, and Alex-ander Gardner in the 1860s and '70s.

The concerns for the members of this project were aesthetic more than scientific. Why did the photographer stand where he did? Why did he tilt the camera this way or that? The answers to such questions tell us what the 19th century photographers thought was important, give us a glimpse of their aesthetics which were, naturally, born of the culture of that time.

Mark Klett sees 19th-century photographs as icons, and says it is ``important for us to go back and see them in our own terms.'' He also speaks of family photographs, of his father lining up the family each Thanksgiving for yet another portrait. While such photography is not concerned with the scientific exactitude, Klett feels ``the urge is the same . . . the desire to see change'' is the same.

The more rigorous repeat photographers try to make their photographs from the identical spot, on the same day of the year and at the same hour and in the same weather as those who photographed before. But there are forms of repeat photography not so exacting, and one example of that is the work done by Bill Ganzel in ``Dust Bowl Descent'' (University of Nebraska Press).

Ganzel's point of departure is the great collection of Farm Security Administration (FSA) photographs made between 1935 and 1943. Between 1975 and 1980 he retraced their steps, and came up with the material for his book.

Ganzel says he ``chose not to replicate the FSA photographs because I was interested in more than just change, more than just how surface appearances altered over time.'' So, when he finally located Florence Thompson, whom we know better as the ``Migrant Mother'' of Dorothea Lange's classic image of the Great Depression, he photographed her with three daughters in suburban Modesto, Calif. Ganzel's interest is, primarily, people, and portraiture is not well-suited to repeat photography, but his work has close ties with it.

It might seem that rephotography deals with great intervals of time -- decades, if not a century -- but that isn't always the case, and it isn't necessary that the object photographed has altered for the worse. In 1979, Frank Gohlke photographed the wreckage after a tornado hit Wichita Falls, Texas. He returned a year later, and the transformation is remarkable: Where there was a house transformed into so many pieces, there is, once again, a house. These photographs are about renewal. The rephotographs, he claims, ``are an attempt to enrich the experience for the viewer. If you're looking at pictures of the same place, and the pictures don't look anything alike, you're forced to ask questions.''

Gohlke's and Ganzel's images may pose different questions than do a scientist's repeat photographs. But it all underscores a point made by Wayne Lambert, editor of Repeat Photography Newsletter, in describing the reaction to seeing the before and after, the then and now of matched pairs of photographs: ``When they're seen together,'' he said, ``they're no longer seen alone.'' Making it easier for future rephotographers

Good rephotography demands good recordkeeping in the first place. To enable photographers of tomorrow to replicate your scenes of today, authors of the ``Bibliography of Repeat Photography for Evaluating Landscape Change'' recommend including this information: station, date, time, location, subject (fairly detailed), film number, film type, filters, exposure, f-stop, developer, developing time, axis right, axis left, lens up, lens down, lens, focus, aiming point, azimuth (of sun), marker, height, and remarks.