Terence Stamp was originally cast as Thomas, but was dropped two weeks before shooting began in favor of the then-unknown actor David Hemmings.
Michelangelo Antonioni's first choice for the role of Jane was the Swedish actress Eva-Britt Strandberg, after spotting her in Bo Widerberg's film Kärlek 65. She went to London to meet Antonioni. He approved of her, but the three MGM bosses present at the meeting didn't like her "big nose". The role went to Vanessa Redgrave.
Michelangelo Antonioni's original choice for the rock band was The Velvet Underground but there were problems over their work permits at the time. The In Crowd (who later became Tomorrow) were then offered the cameo but dropped out at the last minute, and the guitar destroyed by Jeff Beck - probably in emulation of The Who's Pete Townshend - was owned by The In Crowd guitarist Steve Howe.
A silver jacketed Janet Street-Porter can be seen wearing red/yellow striped PVC trousers and dancing to the Yardbirds during the club scene.
According to Don McCullin in his autobiography "Unreasonable Behaviour", director Michelangelo Antonioni was unhappy with the color of the grass in Maryon Park. He had it sprayed green so he could re-shoot the scene.
Among the homeless men whose photos were taken by the David Hemmings character is Julio Cortázar who wrote the original short story on which Blowup is based.
Antonioni's first English language film.
As a way of bypassing the Production Code (i.e. censors), MGM created "Premiere Productions". This was a dummy company which had no agreement or affiliation with the Production Code and, therefore, did not have to adhere to its standards. MGM did not have to cut the full frontal nudity or other sexually explicit scenes and maintained all rights to the film.
Loosely based on the careers of Swinging London's ace fashion photographers David Bailey and Terence Donovan.
Photographer David Bailey was also considered for the role of Thomas.
Reportedly the first British feature film to show full frontal female nudity.
The film contains a rare performance of The Yardbirds during the period when Jimmy Page and Jeff Beck were both in the band. Jeff Beck would leave a few months later.
The photographs featured in the film were taken by Don McCullin.
Thomas' Rolls Royce actually belonged to Jimmy Savile and used to be white but was painted black for the film.
Thomas' workhorse camera was the then innovative Nikon F, the world's first 35mm SLR with full coupling of shutter and aperture with its exposure meter. Even though the particular model had been around since 1959, the glamorous publicity it received in the movie generated an unprecedented enthusiasm among camera buffs, professionals and amateurs alike.