The so-called blue hour is a concept that shows well how natural light coming from the sky changes over time. Each minute throughout the day natural light changes and thus contrast, shadows, colors and tones of photos. Some landscape photographers rightfully claim that, when the sky is clear, great pictures can only be taken after sunrise or before sunset, when the light is soft and the colors are warm. In urban environments, the blue hour is a very particular time to photograph cityscapes in the timeframe between sunset and the darkness of the night.
Once the sun has set, the colors in the sky swiftly shift from light blue and red towards dark blue. At the same time the artificial lights from street lamps, cars and buildings are turned on. Consequently beautiful “night”-photography with a high dynamic range becomes possible. When shooting at night with a pitch black sky, the artificial light is often much too strong and details of the buildings are lost. The timespan that yields the most beautiful contrasts is actually quite short and timing is critical. This article by Ken Rockwell perfectly illustrates the importance of timing during the blue hour.
The image above shows the skyline of Singapore’s financial district just after sunset on a sunny day in march. This amazing view was from the top deck of one of the most breathtaking hotels I have ever seen. Although this motive has been shot thousands over thousands of times since the hotel was finished, I felt very excited when I got my “unique” chance on it, fearing to miss the perfect minute.