"I've documented history and people relate to seeing these images in how it used to be," she told RNZ in a 2022 interview.
Westra was born in Leiden in The Netherlands in 1936 and was educated at a technical college in Rotterdam. She arrived in New Zealand in 1957, armed with a Diploma of Arts and Crafts Teaching and her camera, to visit her father who had settled in Auckland.
She worked for a few months at the Crown Lynn potteries in Auckland but, deciding to see more of the country, she moved to Wellington and eventually took a job in a photographic business.
She joined the local camera club and travelled around the country with her camera, at first hitch-hiking and then in a second-hand car with a mattress in the back.
She was intrigued by the rural Māori way of life that seemed to be disappearing. It was the time of migration to the cities, and her forays into the more isolated communities were as much a case of personal discovery as an attempt to record Maoritanga.
Her most famous and controversial work was "Washday At The Pa" which was photographed in 1964. Intended as a schoolbook picturing a day in the life of a close but impoverished Māori family in Ruatoria, it created a furore.
The Māori Women's Welfare League was outraged, claiming the photographs must have been posed to show such poverty.
The then-Minister of Education, Arthur Kinsella, changed his mind about using the book as a school resource and it was banned from classrooms. Westra said she was perplexed by the uproar.
She told RNZ in 2022 she would be approached by her subjects from decades ago.
"It's fun to be introduced to a great big Māori (man) and they say oh, I was this little boy going through nana's bag trying to look for lollies. It's really lovely that people come over and say who they are and who they were in my photographs."
Thirty-odd years later, she was given a Creative New Zealand grant to create "Washday At The Pa Revisited".
Westra documented ordinary New Zealanders at work and play for more than 40 years, photographing labourers and strippers alike in photographs whose social realism captured an image of New Zealand in those years.
"We used to have our lives so much more out of doors, in sports fields," she said. "We now have to artificially bring that back."
Her work also covered historical events - the tangi of James K Baxter and of Inia Te Wiata, pallbearers of Prime Minister Norman Kirk's coffin, and the protests of the 1970s and 80s.
Westra was made a Companion of the New Zealand Order of Merit in 1998 for her services to photography and in 2007, the Arts Foundation named her as one of its Icon Artists.
In 2015 she received an honorary doctorate from Massey University in recognition of her long-standing contribution to New Zealand's visual culture.
Ans is survived by her half-sister, three children and six grandchildren.
