Wearing a cap saying "Captain", the Hollywood actor-director beams alongside a younger generation of actors in a rare candid photo.

Alongside him - clearly loving the moment - are Ryan Corr (The Water Diviner, Holding The Man, Packed To The Rafters), Firass Dirani (Underbelly: The Golden Mile, House Husbands) and Ben Mingay (Wonderland, Packed To The Rafters).

Dirani has posted the photo, taken at Bondi Beachfest, on Facebook saying "Finally get to work with this guy".

They are part of a large contingent of Australian actors who have been shooting the movie in Sydney, including on location at Bringelly in the western suburbs.

Returning to directing after troubled times, Gibson has an impressive record behind the camera that includes Braveheart, which won best picture, director and three other Oscars in 1996, The Passion of the Christ, a phenomenal commercial success that was nominated for three more Oscars in 2005, and Apocalypto, which was also nominated for three Oscars in 2007.

Andrew Garfield (The Social Network, The Amazing Spider-Man) plays Desmond Doss, a conscientious objector who went to Japan's Battle of Okinawa as a medic and won America's highest military honour for saving 75 lives. A Seventh Day Adventist, he was the only American soldier to fight on the World War II frontlines without a weapon.

The cast also includes Sam Worthington, Vince Vaughn, Hugo Weaving, Teresa Palmer Rachel Griffiths, Richard Roxburgh, Matt Nable and Luke Bracey.

Gibson's son Milo plays a role. So does Weaving's son Harry Greenwood.

Of the three amigos in the selfie, Corr plays Lieutenant Manville, Dirani is Vito Rinnelli and Mingay is Grease Nolan.

Nine weeks into shooting, Hacksaw Ridge and is due to wrap in the second week of December.

The state government contributed an undisclosed sum to land the movie after locations were scouted around the country, delivering what deputy premiere Troy Grant said would be 720 jobs and more than $26 million in production spending to the state.

The movie is the third that Hollywood producer Bill Mechanic has shot in Australia after the historical fantasy The Moon and the Sun in Melbourne and the thriller 2.22 in Sydney.

The Water Diviner's Andrew Knight has co-written the script with Robert Schenkkan (The Pacific, The Quiet American) and Randall Wallace (Braveheart, Pearl Harbour).

At a press conference at Fox Studios in July, Gibson said he appreciated the state government's co-operation in making Hacksaw Ridge.

"This is not like a big studio film," he said. "This is an independent film - it's a large one - but that makes the co-operation that much more meaningful to me."