Paul Sullivan, 50, was described as a “dangerous offender” by police after being caught when a mother saw his messages on her daughter’s phone.
Snaresbrook Crown Court heard he approached five 14-year-old girls in a park and befriended them by supplying alcohol, cigarettes and cannabis.
After they exchanged numbers, he invited the teenagers to his home and gave them more alcohol before starting games like “spin the bottle” that he used to find out sexual information.
The victims later told police that Sullivan would make comments to deliberately make them feel uncomfortable, and on one occasion asked one of them if she would have sex with him if they were alone.
Police said that the visits lasted for two weeks before one of the girls’ mothers called officers after seeing messages showing she had visited an older man’s home.
Sullivan was identified and arrested in Loughton in July 2018 and police seized a laptop and electronic devices from his home.
Analysis found homemade videos of children and other indecent images, some of which he had attempted to hide or delete.
Sullivan, of Cheshire Street in Shoreditch, was convicted of numerous offences at Snaresbrook Crown Court on Friday.
They included two counts of causing a girl to engage in sexual activity, five counts of meeting girls following sexual grooming, supplying cannabis and making indecent photographs of children.
Detective Constable Andy Owen, from the Central East Exploitation Team, said: “Sullivan is a dangerous offender who targeted vulnerable young girls for his own sexual gratification and we are pleased he has now been brought to justice.
“The victims and their families have shown great courage providing us with vital evidence which has led to this conviction. We hope this case demonstrates our commitment to identifying perpetrators of child sexual exploitation and encourages any other victims of this type of crime to come forward.”