NEW YORK—NEW YORK - Today, in the classic photography market, it's not exactly earth-shattering news that a picture has sold for $100,000. But in the mid-1970s, when the first major all-photography auctions were held and connoisseurship was in its infancy, the idea of paying six figures for a photograph was far-fetched indeed.

It would take another decade for the $100,000 mark to be reached. In 1985 New York dealer Peter MacGill of Pace/MacGill astonished the field by selling Paul Strand's Wall Street to the Canadian Centre for Architecture in Montreal for $170,000. In terms of connoisseurship, this picture was as good as it gets. One of Strand's most famous images, it was signed, printed and tipped to vellum by the photographer, and came from the son of the man whose office seved as the vantage point for Strand's picture in 1915. Photography consultant Richard Pare, who was cca's curator at the time, says, "It was one of the quintessential 20th-century images in photography. The price was high, but it would not have come around again." The only other vintage print, unsigned and on lesser-quality paper, is in the Philadelphia Museum of Art.

San Francisco dealer Jeffrey Fraenkel broke the barrier in 1987 with a rich, large-format 1865 albumen print by the French photographer Charles Aubry, titled Study of a Leaf. No other print of this image has ever been found, and Fraenkel says, "In the history of the gallery, if I could have one 19th-century picture back, this would be my first choice."

The six-figure milestone was surpassed at auction for the first time in April 1989. Sotheby's New York photography department head Denise Bethel remembers the sale at which Jane Corkin, now of the Corkin Shopland Gallery in Toronto, bought a a 1927 print of Edward Weston's Nautilus for $115,500, against an estimate of $25,000 to $40,000. "It was everything you would want this Weston to be," Bethel says. "It was on matte-surface paper, signed in pencil with a full signature and dated, and the print itself was stunning." It was also irreplaceable, because the manufacturers of the paper Weston used lowered their paper's silver content the following year. (More silver means richer blacks in the print.) In October of that year, Christie's sold a powerful waxed-platinum print of Edward Steichen's 1902 portrait of the artist George Frederick Watts for $110,000, above the $3050,000 estimate.

Over the next decade, the photography market expanded exponentially. In 1999, MacGill sold one of six known vintage prints of Man Ray's Glass Tears to a West Coast collector for $1.3 million. More and more contemporary art dealers began trading in photographs in the '90s, selling large, editioned color works priced according to contemporary art standards, not those of the traditional photography market.

At auction, intense demand for certain contemporary photographers sent prices through the roof. In February 2002, Andreas Gursky's 1997 Untitled V sold at Christie's London for £432,750 ($613,000), a record for any contemporary photograph. And the trend continues. This past November, a collection of contemporary photographs assembled by Baroness Marion Lambert of Belgium and dubbed "Veronica's Revenge," featuring works by Gursky, Barbara Kruger, Richard Prince and Matthew Barney, went on the block at Phillips, de Pury & Company in New York. In two sessions, 185 lots sold for an astonishing total of $12.5 million, breaking the $100,000 barrier 36 times.

The contemporary photography boom has not led to equally wild spending on traditional photography, however, and the two markets remain largely separate and distinct. Virginia Zabriskie, a longtime New York dealer active in many areas of the art world, including photographs, says, "Dealers in the contemporary area are used to asking high prices, and their clients are used to paying high prices. Besides, there are no connoisseurship issues with this kind of contemporary photography."

On the other hand, says Kevin Moore, the photography expert for Thea Westreich Art Advisory Services in New York, "connoisseurship in vintage photography is about the print. Connoisseurship, at least now, in contemporary photography is about the imageimage in the larger sense, not only the image in the picture but also the image of oneself as an art collector."