Representatives from Christie's, Philips de Pury and Sotheby's say they have seen a sizable increase in auction sales of photographs, compared to this time last year.

The most notable item was Edward Weston's nautilus shell print, which sold in April for $1.082 million, the second-highest-grossing Weston print to date. The print was originally purchased from Weston by amateur photographer Bernice Lovett for $10 in 1927 and has never before appeared on the market.

Other photographs included a collection of 70 Irving Penn prints valued at $3.8 million, collected by Penn's close friend Patricia McCabe, and an Edward Steichen image, "Wheelbarrow with Flower Pots," which sold for $194,000.Overall, the three auction houses totaled more than $18 million in sales.