Usually with a sky full of star trails you can safely assume “Film!” I haven’t yet matched anything like this with the Nikon D700, although it’s bound to happen sometime. If you do want to streak the sky with stars it’s easier with a telephoto – here I used a Takumar 200mm on my old Spotmatic.
Fuji 100 slide film was exposed for at least an hour at f11 or 16, for maximum star streak. In scanning I have softened the magenta cast, this being the colour shift that comes with long shutter times on film. The blue stars are hard to explain; the range of star colours is probably a surprise to most people too. It does take a dark night to get so many stars on your frame, and it is also hard work composing in the very low light transmitted by an f4 telephoto lens.
The location is a closed school at the old mining settlement south of Westhaven Inlet, on the long road to the west coast. The school is now holiday accommodation but the limestone bluffs behind it remain unchanged. The light scatter in the sky can only come from starlight, given the distance from urban life. It was roughly ten days since full moon, so there was no risk of moonlight brightening the sky until 3am. There was no risk of my staying up to see it, either, as we were getting up early next day for the long walk down the Kahurangi coast.
In setting up this shot I was confident that nothing would intrude on it, as the lower slopes are forested and the district is barely inhabited. However something unexpected came up – at least in one sense: the long film exposure cramped my digital creativity with the second tripod. I wanted to start experimenting with the bright outside light of the schoolhouse, but had to finish the film exposure first. So it did not get the full exposure that I had planned for it.