John Foxley, of Borehamwood, Hertfordshire, used his position to sexually abuse and take indecent photographs of boys, Middlesex Guildhall crown court heard.
He pleaded guilty at a hearing in June to one count of indecent assault and eight other charges relating to the taking and distribution of indecent images.
The 54-year-old also admitted aiding and abetting the indecent assault of a child he photographed being abused by another man, Shaun Tyler. Tyler, 37, an American teacher who Foxley met when both taught at an East Sussex school in the 1980s, was jailed for nine months last year. Detective Inspector Ian Hughes, who led the investigation, said: "These men abused the position of trust they had as teachers."