Suddenly sex seems to be everywhere.

At a film festival, it takes hardly any time to notice how much of it there is on screen compared to regular cinema-going.

While there was a time when nudity and sex were part of the lively mix of telling stories in the movies, steamy scenes happen only rarely in Hollywood and Australian films now, raising the question of whether we've become more conservative about sex or whether directors and distributors just want their films to stay below an R18+ rating for maximum appeal in cinemas.

Or maybe there is just so much sex on the web that films can never keep up.

Only three days into the Sydney Film Festival came a Brazilian drama, Kleber Mendonca Filho's Aquarius, about a retired music critic who is battling to keep her beloved apartment from a property development company that has bought the rest of the building.

For a thoughtful reflection on the struggle to retain dignity while ageing, starring 66-year-old Sonia Braga, it was studded with sex. There was a raunchy flashback, a graphic orgy in another apartment and a lusty encounter with a hot young gigolo.

In another early film in the festival's competition for "courageous, audacious and cutting-edge" cinema, the best of three interconnected stories about women centred on simmering desire.

In Kelly Reichardt's Certain Women, a quiet drama set in Montana, newcomer Lily Gladstone plays a ranch hand who stumbles into an evening class and stays for the new teacher, a nervous law graduate played by Kristen Stewart, who has driven for hours from another town.

When they bond in a diner afterwards, this gentle soul returns for each subsequent class. Rather than the intricacies of school law – sitting among teachers who want to know how they can stop students assaulting them and whether they are entitled to a parking space – she learns the tender pain of love, longing and uncertainty.

It's a beautiful tale that outshines two other stories adapted from a book by Maile Meloy – Laura Dern playing a lawyer for a man whose frustration with the legal system drives him to take a hostage and Michelle Williams as a tightly-wound woman who wants an elderly neighbour's stockpile of sandstone to build a house. Just to add a little spice and tension, the former is sleeping with the latter's husband.

Sex is just one part of a complicated family jigsaw in another competition film, Canadian wunderkind Xavier Dolan's It's Only the End of the World.

The sixth film from the 27-year-old director who won the festival competition with Heartbeats six years ago is a stylish drama shot largely in close-up about a playwright (Gaspard Ulliel) returning home after 12 years to tell his family that he is dying.

But that quarrelsome family – played by an A-list of French actors in Marion Cotillard, Lea Seydoux, Vincent Cassel and Nathalie Baye – makes it difficult for him to reveal the tragic news.

A lusty teenage gay sex scene in flashback suggests why some family members might fear what he wants to say. But a strong idea for a film is dissipated by confusing storytelling and constant intense chatter.

Despite the sex, the strongest impression in the festival's early days has been for films centring on substantial issues.

On opening night, Ivan Sen's outback drama Goldstone, a sequel to Mystery Road, had Indigenous detective Jay Swan (Aaron Pedersen) heading to a remote mining town on a missing person investigation.

Reeling from the death of his daughter, he stumbles onto corruption from a mining company executive that extends to the local Aboriginal Land Council and the trafficking of young Chinese prostitutes. It is a beautifully shot and deeply felt look at the importance of the land and exploitation of the less powerful in contemporary Australia, with compelling central performances by Pedersen and Alex Russell as a conflicted local cop.

But for sheer emotional impact, the best early session at the festival has featured Pakistani filmmaker Sharmeen Obaid-Chinoy's two Oscar-winning short documentaries – Saving Face, about acid attacks on women, and A Girl In The River: The Price of Forgiveness, about honour killings.

Her courageous stand against the horrors shown in the films – and her success forcing the Pakistan government to change a key loophole in the law that allows killers to go free if they are forgiven – made for an inspiring Q&A session. She deserved the rare standing ovation that followed.