While most people are asleep at 3.30AM, I was up a hillside, making multiple long exposures of the stars. Which were then stacked into one image to show star trails.
My day began at 2.15AM with the alarm going off...kettle on...flask made...and off we go.
There are a couple of techniques for star trails, taking one long exposure, or taking multiples and stacking them. The advantage of this is less noise in the image, which would make an image appear grainy.
I have a digital remote which allowed me to set up the duration of the exposure, how many shots I wanted to take, and how much of an interval between shots. This type of device is known as an intervalometer, and is commonly used in timelapse photography.
For this shoot I was taking 12 x 5 minute exposures with a 1 second interval. So I had just over an hour to kill once I'd set everything up and took a couple of test shots to check composition. So once the camera was exposing, I drank tea and gazed at the stars, using my iPhone App called 'Star Walk'.
I'm planning another star trail shoot which will involve 30 second exposures, I've picked the location, I'm just waiting for the weather and a moonless sky to coincide.