It was a clear and warm night last week with a nearly full moon at a 45 degree angle, perfect for heading out to the beach for a super long exposure.
I hiked about 1/2 mile down the beach in the dark to an unusual collection of sea stacks and cliffs. It was difficult to compose this because not only could I barely see through the viewfinder, but I wanted to get close to where the waves were breaking. Since I knew it would be at least a 1/2 hour exposure, I wanted to be just out of reach of the biggest wave that would hit during that time.
After watching the waves for about 10 minutes, I set things up, opened the shutter and sat on the beach to wait it out. It was about 28c at 10pm, but it was difficult to enjoy it completely because I was worried about a big wave hitting. I barely got away with this as some waves came very close.
This is exactly what I saw in the viewfinder. Bright as day, and when I looked out, there was in fact the same colours, but very faint to my eye. I actually did no processing to the raw file at all. I just converted it to a TIFF.
The big problem was noise. There were individual pixels that were easily handled with the 'Despeckle' option. But then some areas had these blue and orange blobs that were about 5 pixels in radius. I assume these are heat related blobs. They could only be removed by cloning each of them out. It was not too difficult.
I know that noise reduction involves taking a second exposure of the same length so the camera can compare them. Is there another way to reduce noise?