A Tasmanian woman has been jailed for six months after she was filmed having sex with her boyfriend's 16-year-old son on a video camera set up to film paranormal activity.

The 28-year-old woman, who cannot be named for legal reasons, pleaded guilty to seven counts of unlawful sex with a minor at Hobart Supreme Court.

The legal age of consent in Tasmania is 17.

She was sentenced to 12 months with six months suspended and has been ordered to attend a sexual rehabilitation clinic.

"You must bear full responsibility for what happened," said Justice David Porter. "Although the relationship that commenced was more opportunistic than predatory, that cannot truly be said of your conduct later on."

The court heard that her partner of 11 years set up a camera in their kitchen in October 2012 to film ghosts but got an even bigger shock when he found footage of his lover and 16-year-old son kissing and cuddling.

The woman allegedly confessed to having sex with the boy on numerous occasions and said she was "ashamed and embarrassed" by her actions. She also claimed she thought the age of consent was 16.

It later emerged that the affair began when the woman, who has an 18-month-old son with the boy's father, went into her stepson's bedroom to discuss his driving lessons.

According to prosecutor Jackie Hartnett the conversation soon turned to tickling which then led to full-blown intercourse.