By 2030, it's estimated more than one in six Canberrans will be over the age of 65; by 2050 it will be one in five. But, according to Australian Association of Gerontology ACT president Chris Hatherly, it's not something society has come to terms with yet.

''Ageing is highly stigmatised in society. Even people growing older themselves don't like to think about getting old, and all the health and physical conditions that come with that,'' he said.

The association hopes a collection of five video portraits of Canberrans approaching their 100th birthdays might propel the issue into the spotlight, and encourage the community to join a discussion about growing old.

A trailer for The Centenarians: Embracing the Coming of Age will be shown at the Silver Screen Film Festival on Tuesday night, before a screening of feature documentary Ping Pong, which follows the story of eight elderly table tennis players.

''There's a fair bit of stigma, there's a fair bit of ageism,'' Dr Hatherly said. ''In a sense, ageism could be the last 'ism' that Western society has to deal with.''

He said sexism and racism were often the topic of a public conversation but ageism - which included older people being ignored, discriminated against, or even aged care services being underfunded - wasn't spoken about.

But the film itself won't be a lecture in ageing, and will instead be a celebration of fascinating stories that have stretched over Canberra's 100 years.

''They're stories about getting old, but they're also stories about people who've lived really full and rewarding and interesting and in some cases quite extraordinary lives too,'' he said.

''I think what we're trying to do is promote the idea that ageing can be a positive experience. Sure, there are health and physical things that often come with ageing but, generally speaking, there are people who do reach old age successfully, and have amassed a wealth of relationships and experience and wisdom over those years.''

Included in The Centenarians is 92-year-old architect Romaldo Giurgola, who designed the new Parliament House, and described himself as a ''young'' Canberran as he only moved to the capital late in life.

He said it was important to value older members of the community as a link to knowledge through history.

''Old age is a good age … not only in life, but also in the environment,'' he said. ''You always learn from the past … it makes you aware that humanity is not born today.''

Dorothy De Low, who at 102 (''and three-quarters'') years old is the world's oldest table tennis player and was one of the stars of Ping Pong, arrived in Canberra on Monday to attend the opening of the Silver Screen festival.

She said table tennis had been a passion since she was 50, when she switched to the sport from tennis.

''I like the company and that sort of thing,'' Mrs De Low said. ''I like to win, of course, but it's not that important. It's meeting my friends and having a lot of fun.''

She lives independently at her Hurstville home, and, despite having macular degeneration, still plays up to three nights a week at table tennis clubs in Sydney.

The Silver Screen Film Festival runs until August 27 at Arc Cinema at the National Film and Sound Archive.