Wayne Bayliss, 45, took photographs on two separate occasions, and admitted charges relating to indecent images of children.
He was jailed for two years and four months by Judge Peter Barrie at Shrewsbury Crown Court.
The judge told Bayliss, of Meadowbrook, Bayston Hill, that he could not be trusted in public with a camera phone.
The court heard that Bayliss had admitted breaching a sexual harm prevention order, three counts of making indecent images of children, one count of possession of a prohibited image and distributing indecent images of children.
Andrew Wallace, prosecuting, told the court that in September 2016, in Blackpool, members of the public contacted police regarding concerns that Bayliss, was taking pictures of young girls entering the Winter Gardens entertainment venue.
Bayliss was arrested nearby in possession of a mobile phone and a camera, and they contained indecent images as well as pictures he had taken.
On examining the phone, police found he had sent a category A image to someone, with a message saying the person in the photograph was 'one of my victims'.
The offence in relation to breaching his order happened in Shrewsbury in July this year.
Bayliss approached a family, which included two young girls, and asked them for directions in Clermont Street.
He had a mobile phone near his chest, and the family were concerned that he was filming them and the father challenged him and asked for the phone off him.
It was noted that he had two phones on him at the time, and police were called and the children were left upset and distressed. Judge Barrie described the second phone as a 'decoy' phone.
Bayliss was arrested, and when police asked him for the pin codes for his two phones, he refused, which put him in breach of his order.
Mr Wallace explained this was the third time Bayliss had committed these types of offences, after he was jailed in 2014.
Stephen Scully, defending, said his client was 45, had learning disabilities and epilepsy, and said he has been unable to find work.
He said: "He is somebody who gets bored, and when he gets bored unfortunately he is filling is time carrying out behaviour that he shouldn't be doing."
He added his client had completed a sex offenders group work programme in 2004 and he was desperate to get help.
Judge Barrie said: "I can not properly deal with you except by way of immediate custody.
"This was a serious and persistent breach and you had planned to avoid it with a decoy phone.
"It is impossible to trust you in public with a camera that has a phone."
Judge Barrie revoked a previous order, and put in place a new sexual harm prevention order which banned Bayliss from having a camera phone in a public place.