NEW YORK—Christie's is offering the collection of German photographer Gert Elfering. Christie's photography specialist Joshua Holdeman says the group of works is significant because Elfering, a man of "ample means," was able to buy what he loved, and hence has a collection that highlights many great works of the 20th century, including prints by Man Ray and Edward Weston, but also including contemporary work such as that of Thomas Demand. The backbone of the collection, however, are works by photographers that Holdemann characterizes as bridging the gap between the worlds of fine art and fashion, photographers like Helmut Newton and Irving Penn.

Christie's is also auctioning off a rare cache of 40 dye-transfer flower photographs by Robert Mapplethorpe, estimated at over $1 million. Holdemann tells artinfo.com, "There was a period in the mid to late 90s when Mapplethorpe's market was kind of soft, but in the past three or four years his work has been re-contextualized. He has taken his place in art history and the market has responded accordingly." Holdemann feels confident the pictures will do extremely well.

Another highlight of Christie's photographs that Holdemann points to is a Diane Arbus print from 1965 that was shown in the famous "New Documents" exhibition at the Museum of Modern Art the following year, alongside works by Lee Friedlander and Garry Winogrand. The vintage print of a family at a nudist camp is estimated to sell at $250-350,000.

Sothebys has 34 lots from the collection of Joseph and LaVerne Schieszler, who, according to Sotheby's photo expert Chris Mahoney, began collecting photographs in the 1980s after collecting in other fields. "They were experienced collectors by the time they came to photography," he says. "It's important because by the time they began collecting photography they knew the pitfalls other collectors could fall into. They did a lot of research, were very patient and visited auction houses and galleries and spoke to dealers in a quiet way." One major highlight of the collection, he says, is an iconic Andre Kertesz photograph of 1926, Chez Mondrian, which depicts the vestibule of Mondrian's apartment in Paris. Many prints have been made of this photograph, but this one is vintage, made in the same year as the negative, and is in extremely good condition. It is estimated at $400-600,000. Other works in the collection are by Dorothea Lange, Man Ray, Edward Weston and others. "Their focus was always on the print quality and condition," Mahoney says of the Schieszlers. The Kertesz, he says, is a great example of this. "It has all the bells and whistles," he says. "and it's like a time capsule from 1926."

Mahoney also points to one of the highlights in Sotheby's various-owner sale. It is a Diane Arbus, also an iconic image, of a boy holding a toy hand grenade, from 1962. Estimated at $350-500,000, the photograph is a vintage signed print, and, he says, a very rare example. "Arbus was not successful enough in her lifetime to make a lot of prints," Mahoney says.

Phillips, meanwhile, has material from the Ann and Jurgen Wilde Collection. These two German collectors built up a group of photographs from the likes of Karl Blossfeldt, Albert Renger-Patzsch, Florence Henri and others. Proceeds will benefit the Wilde Foundation. A highlight is Renger-Patzsch's Isolatorenkette, 1925, estimated at $30-50,000. Among other collections the house is offering is selections from that of Ted and Joyce Strauss, collectors since the 1970s. A highlight is a complete set of Nicholas Nixon's series The Brown Sisters, estimated at $150-200,000. Nixon followed the family from 1975 to 2004.