SF was a science fiction fanzine by John Lawrence Magnus, Jr.
SF was published by the Hopeful Young People's Extra-Radical Society for the Promotion of Amiable Conditions Everywhere (HYPERSPACE) in Silver Spring, Maryland, U.S.A. in the 1950s. The first issue appeared in September 1952, with #2 in October, #3 in November, and #4 in December of that same year. Issue 5 was released in January 1953, #6 in February-March, #7 in June, and #8 in December 1953. The title of the fanzine was then changed to Vamp for issue #9, and Varioso for issue 10. He continued to release Varioso till 1958, with 18 issues published.
SF featured columns by Richard Bergeron (Warhoon), Don Cantin, Dick Clarkson, Andrew Conn, and Philip F. Paige.
Contributions of poetry came from Isabelle Dinwiddle, and John L. Magnus.
SF was a member of "Fanvariety Enterprises", an affiliation of fan publishers put together by Max Keasler and Bill Venable. It included such publications as Max Keasler's Opus, Bill Venable's The Pendulum, Norman Browne's Vanations, Harlan Ellison's Science Fantasy Bulletin, David English's Fantasias, Bob Farnham and Nan Gerding's The Chigger Patch of Fandom, Norbert Hirschhorn's Tyrann, Ian MacAuley's Cosmag, Joel Nydahl's Vega, and Starlanes by Nan Gerding and Orma McCormick.
John Magnus was a member of the Baltimore SF Forum, hosted by Marian Oaks (The Femzine) in the late 1950s. The group, which included John Hitchcock, Raleigh Multog, Ted Pauls, George Wetzel, and Ted White (Zip, Stellar, Void), met monthly till around 1962.
In 1953-1954, John Magnus was also editor of The National Fantasy Fan. From 1954 till 1958 Magnus published Varioso, and in 1958, he released the title Rumble.