That must've been very hard, if they were the blue penguin they are the smallest penguins in the world.
If they were the yellow eyed penguin then they are super rare and you better take the shot when you see one in their natural habitat (they swim in from the sea and walk towards the beach during sunset time).
And I'm fairly certain you didn't see the crested penguin (the ones with big yellow eyebrows) because they live deeper in the rainforest closer to west coast.
Anyways, point being sighting penguin and shooting them in South island isn't easy since we only have the small rare almost extinct species. You need a camera you are either very familiar with or very easy to use.