A Perth lollipop man has been found guilty of filming himself sexually abusing young girls, including a one-year-old child.

Warning: This story contains details which some readers may find disturbing.

Michael Cyril Hyde, 60, had been on trial in the District Court for the past week accused of eight child sex offences, including persistently engaging in sexual conduct with a child and producing child exploitation material.

The jury deliberated for about an hour-and-a-half before finding him guilty of seven of the charges relating to the abuse of the one-year-old, the indecent filming of her older sister and the sexual assault of two sisters from another family when they were aged 6 and 7.

He was found not guilty of the eighth charge, which alleged he had indecently recorded a young boy.

The court was told Hyde had used a hand-held camera to film himself abusing the girls and the recordings were discovered by police when they searched his home in April 2016.

Hyde befriended baby's mother

Hyde worked as a traffic warden at a primary school in Perth's affluent western suburbs. ( Supplied )

Hyde's abuse of the baby started after he befriended her mother and gained her trust while he was working as a traffic warden at a western suburbs primary school.

He denied any wrongdoing, testifying that there was nothing sexual in what he had done.

The jury members were shown hours of what were described as "confronting" recordings of the abuse, and after they delivered their verdicts today, Judge Felicity Davis thanked them for their attention.

"It was a particularly confronting thing you had to do, watching those hours of videos," she said.

"It was an onerous task but an important one, and I thank you very much for accepting your public responsibility."

Images amongst worst detective had seen

At the start of the trial, Hyde pleaded guilty to a charge of possessing more than 26,000 images and videos of child pornography, which the court heard had been described by one detective as "some of the worst he had seen in his career".

Hyde was convinced he had done nothing wrong, Judge Felicity Davis said. ( ABC News: Kathleen Dyett )

Judge Davis ordered that psychological and pre-sentence reports be prepared on Hyde to help determine what sentence he should receive, although she said she did so with "misgivings" because of his denials.

"I don't believe a word of his evidence … he has obviously convinced himself he did nothing wrong," she said.

"Everything he said was totally inconsistent with what we saw him do and heard him say on those videos."

Hyde was remanded in custody until he faces a sentencing hearing in August.