The shot was taken during summer vacations in Dolomites. In the twilight I took the exposure for the mountains and then one additional shot with underwater light in the lake for the green colour of the water. When the stars appeared I did one more shot for the sky. For the whole 3-4h of waiting I did not move the tripod even for an inch, so the exposures are blended without repositioning/compositing. I am always blending night shots only to improve the technical limitations of DSLRs, not to change the natural scenery (sky replacement, milky way repositioning etc.).