James Franco is making a documentary about the porn industry after realising it isn't easy to turn people on by having sex on film.
The 127 Hours star once shot a sex tape with his girlfriend and was so disappointed with the result, he vowed never to make another one.
The experience gave him a new respect for porn stars - because they really know how to sell sex.
He says, "When I was young, I got a video camera and my girlfriend and I decided to film ourselves and watched it back and said, 'Yeah, well, let's never watch that again.'
"Those people in pornos, they are great performers; they're not just doing it, they're selling it to an audience... They're performing so that an audience can get turned on by that kinda thing.
"My girlfriend and I didn't know that, so it was just kinda like weird movement... It was really boring."
And now the actor/director is planning to make a film about a porn giant, based in San Francisco, California.
He adds, "I actually am very interested in pornography... I watch it, who doesn't? I'm making a documentary on pornography. There's this amazing facility in San Francisco... They do everything in house, they build their props in house. It's an incredible place."