Senior Constable Marc David Osborn, 42, was charged with three counts of filming a person engaged in a private act with the purpose of obtaining sexual gratification.
Osborn had denied filming the acts for sexual pleasure, saying his motivation was to show his younger colleagues that "the old man's still got it".
However, in Downing Centre Local court on Tuesday, Magistrate Janet Wahlquist found Osborn guilty of the crimes, saying he did obtain sexual gratification from the acts.
Ms Wahlquist said that in one video Osborn "winks at the camera" while having sex with one of the women to demonstrate that he was a "sexually adventurous and virile lover".
"It shows he felt good about himself," Ms Wahlquist told Downing Centre Local Court on Tuesday.
Osborn filmed explicit sexual encounters with three women he met on dating websites.
He then uploaded the videos to his computer and put them onto his iPhone to show his colleagues.
The court heard he called the encounters "events" and talk around the police station often was "have you seen Osborn's latest video?".
The women were present in court.
Osborn, who dressed in a dark suit, had his bail continued.
He will be sentenced on September 26.