Both pictures above from DragonCon in Atlanta, 1993. In the left picture, and at left in the center picture, is Robert Bloch, who lived 1917-1994. He was primarily a fantasy and horror writer, along with a few straight science fiction tales, and is best-known for his 1959 novel Psycho, from which the 1960 Hitchcock film was made. Bloch's 1958 short "The Hell-Bound Train" won a Hugo, and he was given a Special Hugo Award for his career in 1984. His 1993 autobiography is Once Around the Bloch, and he has an "Unofficial Homepage". At right in the center picture is Julius Schwartz , born 1915, who is an agent and editor. He and Mort Weisinger published the first true SF fanzine, The Time Traveller, in 1932. Starting in the 1940s Schwartz became a major force in the DC Comics revival of "superhero" characters, including The Flash, Green Lantern, Hawkman, Adam Strange, The Atom, and Batman.
Above: Jack Williamson now and then: above left is Jack at LibertyCon in Chattanooga, Tennessee, 1995. At right is Jack also signing for fans (he's a nice guy), that time at the 1939 New York WorldCon - Fred Pohl is behind him and in upper right may be Donald Wollheim. Jack's most famous story is The Humanoids, a great novel, and his first story was published in 1928, even before "science fiction" was thus named! Thus he has the longest career in SF history, and is still doing fine work, as with his wonderful "The Firefly Tree" in 1998's Year's Best SF 3 (edited by David Hartwell). The SF Writers of America named him a "Grand Master" in 1975. Amazingly, there seems to be little about Williamson on the web - ISFDB has a bibliography, and SF Site has a good recent interview with him. (1939 photo owned by Howard DeVore).