Elisabeth Lanz and co-star Jorg Schuttauf are acting in Out of Ashes, a television movie based on United States novelist Emilie Richard's work, for German network ZDF.
The programme was being filmed in Akaroa and Dunedin, including Victory beach at Okia Reserve and Smaills beach, by German production company Polyphon International.
Out of Ashes will air in a Sunday-night primetime slot to more than 7 million viewers.
The Yellow Eyed Penguin Trust had given the production company permission to film in the reserve, but with strict guidelines to protect the penguins and their habitat.
Trust chief executive Sue Murray said no filming was allowed near nesting sites and no real penguins were filmed.
The company had wanted a genuine penguin habitat for the movie, which was based around a marine biologist (Lanz) who runs away from a violent marriage to start a new life in New Zealand, where she gets to work with yellow-eyed penguins.
She finds an injured penguin and helps save its life.
Mrs Murray said she had so far been impressed with how environmentally conscious the film crew had been.
It had constructed its own hide and brought fake penguins as props.
The company was paying fees for filming in the reserve and the money would go back into conservation efforts in the reserve, Mrs Murray said.
It was not yet known how much the filming would raise.
Lanz, who plays zoo veterinarian Dr Mertens in a popular German show, said while she was used to filming with animals such as elephants and giraffes it was in a controlled zoo environment, so it was completely different filming "in the wild" in New Zealand.
Yesterday, the crew was filming one sand dune over from a large male sea lion.
"It is my big adventure.
''This is real life.
''It's fantastic."
Her role as Dr Mertens meant she was often asked to promote wildlife causes and was keen to try to raise the yellow-eyed penguin's profile back home, she said.
"I'd like to make some connections."
