A former secondary school principal has faced court after being accused of secretly filming and taking photos of a woman in the shower.

The Geelong Magistrate’s Court's been told 66-year-old NOEL LOGAN, of Newcomb, gained access to the ceiling of a house last year.

The court was told LOGAN repeated the offence three times over two weeks.

LOGAN retired from his job as principal at Corio North Secondary College in 2001 after a career of more than 40 years.

He's pleaded guilty to stalking and using an optical device to keep a person under surveillance, and is due back in court on Friday.