No jail for Sydney teacher who filmed up students' skirts and collected child porn.

The schoolteacher comes from a distinguished family of judges.

A disgraced Sydney teacher, and son of two judges, has avoided jail after filming up the skirts of his students and possessing almost 10,000 images of child pornography and seven videos in the most serious classification.

Former St Andrew’s Cathedral School maths teacher Robert Emmett – then 36 – made two videos of three 14-year-old girls’ underwear on his mobile phone without their consent as he chatted to them between classrooms in March 2013.

He is the son of NSW Court of Appeal judge Arthur Emmett and Federal Circuit Court judge Sylvia Emmett and the grandson of former chief justice of the NSW Supreme Court Sir Laurence Street.

The Downing Centre District Court heard Emmett had been diagnosed with complex psychosexual problems, with “voyeuristic, paedophile, hebephile and fetishistic features”, Fairfax Media reports.

His lawyer said he was taking medication to suppress his sexual libido.

One of the female victims told the court in a statement: “When I think back on his behaviour, he was often looking up the stairs as we walked up and down, and hanging around us too closely at lunch times.”

Judge Ian McClintock said the child pornography was “disturbing and depraved”, but that Emmett’s early guilty plea showed insight into his actions and he was making progress in his rehabilitation.

Emmett received a two-year Intensive Correction Order to be served in the community. He must undertake 32 hours of community service each month and take part in treatment programs.

He also received a three-year good behaviour bond for filming up women’s skirts at railway stations.

After learning of the offending, the school advised parents Emmett had “never set foot in the school again” following his “reprehensible behaviour” and that the girls involved were offered counselling, the ABC reports.