Thousands gather for naked Spencer Tunick Opera House photos

THOUSANDS of people have gathered at Sydney Opera House ready to strip down and have their photograph taken by renowned artist Spencer Tunick.

THOUSANDS of people have gathered at Sydney Opera House ready to strip down and have their photograph taken by renowned artist Spencer Tunick.

Crowds began gathering from 3am (AEDT) with more than 2500 eager participants assembled by 4.30am.

The American artist will begin taking his photographs for the work, called The Base, from 6.15am.

There is a broad mix of participants, among them a pregnant woman, who will be taken to hospital after the installation to be induced.

Student, Art Rush, 19, said he was thrilled to be among it.

"I'll never get a chance to do this again, it's not worth being inhibited," Mr Rush said. "It doesn't feel sexual, it just feels tribal - a gathering of humanity.

"I thought it would be all old people and nudists, but everyone here is great."

Advertising creative director Adam Sutherland, 46, said he hadn't decided whether to tell his employees, while Nurse Nerida Grant, 27, said she wouldn't miss it for anything, saying: "I love (Tunick's) art work, it's fun."

A spokesman for the event said they were thrilled with the participant turnout, with cooler temperatures not deterring anyone from stripping.

The installation will take place on the steps of the Opera House as well as inside the concert hall.

The work has been commissioned by the Sydney Gay and Lesbian Mardi Gras.