Question: Who is the photographer associated with the New York School of Photography whose used his camera as a tool for social reform.

<P0-S0> Lewis Wickes Hine (September 26, 1874 – November 3, 1940) was an American sociologist and photographer. <P0-S1>  Hine used his camera as a tool for social reform. <P0-S2>  His photographs were instrumental in changing child labor laws in the United States. <SEP> <P1-S0> Joseph Rowntree (24 May 1836 – 24 February 1925) was a Quaker philanthropist and businessman from York, England. <P1-S1>  Rowntree is perhaps best known for being a champion of social reform, partner and friend of Charles Booth, and his time as a chocolatier at family business "Rowntree's", one of the most important in Britain. <P1-S2>  Even as a powerful businessman, he was deeply interested in improving the quality of life of his employees; this led to him becoming a philanthropist, pursuing many charitable causes. <P1-S3>  In 1904 he created three trusts, the Joseph Rowntree Village Trust (JRVT) which was originally set up to build and manage the garden village of New Earswick, the Joseph Rowntree Charitable Trust (JRCT) and the Joseph Rowntree Social Services Trust (JRSST). <P1-S4>  The latter two were both set up to effect social reform, the difference between them being that whereas the Charitable Trust was set up as a charity, the Social Services Trust was set up as a limited company so that if necessary it would be able to undertake social and political work not legally allowed by a charitable Trust. <P1-S5>  He suggested that only the JRVT would be permanent but in fact all the trusts are still in existence although the Social Services Trust has changed its name to the Joseph Rowntree Reform Trust and with the separation of the Joseph Rowntree Housing Trust from the Village Trust in 1968, there are now four trusts that exist today. <SEP> <P2-S0> Saul Leiter (December 3, 1923 – November 26, 2013) was an American photographer and painter whose early work in the 1940s and 1950s was an important contribution to what came to be recognized as the New York school of photography. <SEP> <P3-S0> The New York school of photography is identified by Jane Livingston as "a loosely defined group of photographers who lived and worked in New York City during the 1930s, 1940s and 1950s" and who, although disinclined to commit themselves to any group or belief, "shared a number of influences, aesthetic assumptions, subjects, and stylistic earmarks". <P3-S1>  Livingston writes that their work was marked by humanism, a tough-minded style, photojournalistic techniques, the influence of "film noir" and the photographers Lewis Hine, Walker Evans, and Henri Cartier-Bresson; and that it avoided "the anecdotal descriptiveness of most photojournalism" and the egoism of American action painting, and indeed that it was remarkably little influenced by contemporary painting or graphic design (even though a number of its exponents had direct experience of these). <P3-S2>  Livingston selects as key exponents of the New York school of photography Diane Arbus, Richard Avedon, Alexey Brodovitch, Ted Croner, Bruce Davidson, Don Donaghy, Louis Faurer, Robert Frank, Sid Grossman, William Klein, Saul Leiter, Leon Levinstein, Helen Levitt, Lisette Model, David Vestal, and Weegee.