Naked Ambition, An R-Rated Look at an X-Rated Industry is less of a documentary and more of a video diary by celebrity photographer Michael Grecco about the making of his book, Naked Ambition.

The film begins with two well-dressed Asian businessmen sitting, silent and austere, next to a gyrating, robotic dildo on a mechanized arm. For several bizarrely entrancing moments, the faux penis continues to jack hammer away before the credits begin to roll over music that sounds like it could have come from a hipster funhouse.

At least you know what you’re in for: a tongue in cheek (if you’ll pardon the pun), comically personal look at the sex industry. Naked isn’t as titillating as it is fascinatingly unusual.

What Grecco describes as his “Fellini-esque” obsession with all subcultures led him to the Adult Video News convention and its grand finale, the AVN Awards, also known as the “Oscars of Porn,” in 2006 to document the performers, stars and fans of the $12 billion a year porn industry. Grecco wanted to insure that both the film and the photos were intimate, tasteful and revealing, setting out to show pornographers without creating porn.

The film primarily follows Sunny Lane, a young, homegrown, strawberry blonde who trained to be an Olympic ice dancer but now dreams of winning an AVN as Best Newcomer, saying, “That’s what I worked my ass off for,” and Joanna Angel, a Rutgers graduate who once debated between becoming a teacher or working in porn and is also nominated for Best Newcomer. Grecco uses both women to illustrate that porn stars are intelligent, driven, committed performers.

He’s quick to point out there seems to be no shame at the convention, that all the performers are happy and well adjusted, devoid of the shame the industry once implied.

But that is the fault in Naked.

Grecco has created portraits; surface snapshots of people rather than in-depth investigations into the minds of these performers.

If porn stars are so well adjusted, why is next season of “Celebrity Rehab” populated by four former nude models or sex performers? Jenna Jameson, who Naked holds up as the deity of porn, has been extremely brave in publicly sharing her personal history of abuse and neglect. The sex industry is not the happy, bouncy, squeaky-clean world of pasteurized sex Grecco makes it appear to be.

In the end, Naked only scratches the surface and gets to first base.

Grade: C

Naked Ambition releases in select theaters May 1.