The photographer had co-founded Tracks magazine in 1970 with Alby Falzon and David Elfick, and together they filled the pages with photos of their mates, stories about surfing, tips on how to cook and build your own house, and articles on environmental issues.

They also spent plenty of time on and around the beaches of northern NSW, and Witzig was there to capture life on the coast.

These images – many spontaneous shots of young men in the water, on the beach or in various coastal settings – now form part of a new exhibition at the National Portrait Gallery, one that presents the very kind of snapshot that Witzig had intended with his work of a free-spirited but politically conscious lifestyle that played out during the age of conscription to Vietnam.

Curator and historian at the National Portrait Gallery Sarah Engledow had always been taken by Witzig's work, especially the close-up surf portraits that formed part of the national collection, and had long planned to use them for an exhibition.

And she was also struck by how much they reminded her of the large-scale ink drawings of beachside scrub by Nicholas Harding, another artist who is represented in the gallery's collection.

Although the two artists had never met, Ms Engledow discovered the two shared a mutual appreciation of each other's work, and decided to blend the works together in one show, along with film footage of Alby Falzon's surf film Morning of the Earth.

She said the show was about sensations and atmosphere, rather than a particular narrative.

''This show is about textures, it's about smells, it's about the texture of neoprene and weatherboards, and sand and banksia, salt in the hair,'' she said.

At the official opening on Wednesday, Witzig said he was thrilled to see his images blown up to such a large scale, and that he was seeing details he had never noticed when he first took them decades ago.

''I never did any staging, most of it is completely happenstance,'' he said.

''What I was trying to do was record the life that was around me, and that I was part of, clearly.

''I kept on shooting self-portraits, mainly just to amuse myself, but obviously there was something of an archivist about me, of wanting to record my own life. The whole thing is like a self-portrait of a period of time and a group of people, and it's sort of my life.''

Harding was also at the opening, and said that seeing his work alongside Witzig's images added a new dimension to his ink renderings of pandanus trees on the north coast.

''I can see the relationship, and the way Sarah has curated images together … the way the pandanus clings, it has that salty, crusty tang. For me, the pandanus are like allegorical figures in the landscape.''

Witzig said he had always fantasised about taking home one of Harding's drawings whenever he saw them exhibited, and that seeing their works hanging side by side was a thrill.

''This is a landscape I know absolutely intimately, I've known it my whole life, since I was 15 or 16, so it stinks of the country I know,'' he said.

Arcadia: Sound of the Sea at the National Portrait Gallery until October 19.