This images taken in the Brecon Beacons, Wales, uses stacking to combine nearly 1000 30-second exposures for a total exposure time of 8 hours. As I was so close to the foreground elements I had to focus stack to ensure sharp focus from front to back. I had to run the camera on an external battery source that was kept warm with hand warmers and also had a lens warmer wrapped around the lens to prevent any dew or mist on the front glass.