And now here's Bob Hawke, former prime minister, legend, sipping from an identical pink straw. The lines in his face, his grey hair, the glint in his eye, remind me of my father and I want to cry, or smile, remembering a man, and a life well lived. Both my father and Hawkey.

A good portrait will do that to you.

"A portrait is an image of a person where anyone who is looking at that image can gain a strong sense of something about that person," says Christopher Chapman, senior curator at the National Portrait Gallery and one of the judges for the National Photographic Portrait Prize.

"We're all drawing on our own life experience and that will affect how we view any of these images."

It's easy to wonder what the symbolism of the milkshake is in the Hawke portrait but photographer Harold David admits that all his planning went out the window the moment Hawke turned up for the shoot with the drink.

Chapman, and his fellow judges - Robert Cook, curator of contemporary design and international art at the Art Gallery of Western Australia, and Petrina Hicks, an acclaimed Sydney-based photographer - spoke a lot about teamwork when they whittled down the selection.

"A good portrait is always a collaborative idea," Chapman says. "There has to be this sense of trust, this idea of working together to get the image, to allow a sense of truthfulness to come through".

More than 3200 entries were received for the 2018 competition, the most yet. There were entries from recognised photographers and aspiring photographers entering the competition for the first time. 2017 winner Gary Grealy made the cut again with his portrait of artist eX de Medici. Grealy has been a finalist nine times.

"This is the 11th year of the prize," says Chapman, "and they've all felt a little different."

He says the judges don't ever set out to curate to a theme or to reflect any certain idea.

"But if I had to characterise this year's I would call it 'tentative optimism'.

"There's a real sense of Australia as a culturally diverse nation, there's a sense of relaxedness that comes through, a sense of calmness and openness."

One such photograph is Stuart Miller's Kayla. Kayla Doyle is a Murrawarri/Gomeroi woman who identifies as Muslim. She's posing in her front yard with her five daughters, a glorious mixed little bunch of contrasting looks, her Lebanese-Australian husband Khaled and her father, Aboriginal elder Glen. Here's our home, our life, our Australia.

In some senses, several of the portraits this year are quite confronting. Adam Ferguson's Roo shooter's offsider is likely to provoke reaction. Dwyane John is seen holding a dead kangaroo after a night's shooting out past Plumbago Station in South Australia. It's his job to haul the carcasses onto the back of a truck.

"I guess there's at least two very strong symbolic aspects to this image," says Chapman.

"One is that it's a very raw image of outback Australia and there's a sense of toughness and, not so much cruelty, but the live-and-die nature of what it means to survive in the outback.

"But it can also be read as something very gentle, cradling the kangaroo in that way."

Stephanie Simcox's Joey won the Art Handlers' Award on March 22, a prize picked by those responsible for receiving and then hanging the works at the National Portrait Gallery.

"We were drawn back to Joey as the work invites the viewer into a closer observation. The figure has a beautiful relaxation at first glance but tension is also evident in the pose. The painterly aspect with the blue and deeper tones appealed to us and the composition brought to mind many figurative classical works, but in a modern context," said a spokesman for the art handlers.

It is one of two images of men in water, and water is traditionally seen as a feminine symbol, says Chapman. The other is Renee Stamatova's The Arrival, a portrait of a man named Arif, taken in Macedonia just days before Stamatova moved to Australia.

"There was quite an interesting dynamic in both of these photographs," says Chapman. "Both photographers were women, water is usually associated with the feminine, we liked both these portraits."

In Joey, the subject's eyes are closed and Chapman said the judges noticed, after the fact, that many of the portraits were one or the other.

"If there's two types of photographs in the exhibition, there are some where you get a very strong direct sense of the person in the photograph looking directly at you and that emotional connection sometimes might be defiant, sometimes it's vulnerable, sometimes its a mixture of both.

"And there are some others where the person is looking slightly away from us and they're absorbed more in their own world and yet that stills tells us something about the person they are."

Indeed one portrait is the back of someone's head. Colin had a brain tumour removed and a large scar, and indentation, are evident in Nicole Well's striking photograph Scarred. A story told even without a face.

In this year's prize several photographers have used different techniques to capture their subject.

Julia Cameron's The Queen of Deakin is a Polaroid print of an elderly Canberra woman, Alison. Chapman believes it's the first time a Polaroid has been chosen as a finalist.

Adrian Cook has captured activist Yassmin Abdel-Magied using the wet-plate collodion process in a tintype print.

Dianne Jones has photoshopped herself into a portrait in a house of parliament in The Great Echo Chamber; each pose, each character representing different emotions and ideals.

David Rosetzky has used a gelatin silver print to capture ballroom dancer Lyu Masuda in Lyu with orchid, part of an ongoing series where he uses analogue, black and white, double-exposure photographs taken with a 35mm film camera.

"Working with this technique enables me to combine one image with another in a way that I cannot completely anticipate," Rosetzky says.

"It is precisely the random nature of this process that holds particular interest for me – with its inherent misalignments and compositions created through chance."

Is that the way, going back to the Bob Hawke print, say, the best portraits are captured? Is there an element of chance, even if the sitting was well planned through that teamwork Chapman said the judges talked about?

For as much as exhibitions such as this tell a much larger story, about the subject, indeed about our nation, are they all just a moment captured?

The National Photographic Portrait Prize at the National Portrait Gallery, Canberra, until June 17.