The 53-year-old man, who cannot be named for legal reasons, told the High Court in Edinburgh the man confronted him at his property in the city on last August.
He said he had been preparing to take pictures of an aspiring 17-year-old model, Laura Colquhoun. He told the court they had conducted a number of photo shoots and had sexual encounters. Prisoner Garry Faulds, 21, and Miss Colquhoun, of Paisley, have pleaded not guilty to assault, robbery and attempted extortion. The trial continues.