Twilight phases at Sunrise:
- Astronomical twilight
- Nautical twilight
- Civil twilight
The length of twilight before sunrise and after sunset is heavily influenced by the latitude of the observer; therefore I will not discuss the length of each twilight phase since it is highly variable. The first phase of morning twilight is known as astronomical twilight. This period of twilight occurs when the center of the sun is between 12° and 18° degrees below the horizon and slowly increases before day time officially begins.
Most casual observers would consider the entire sky already fully dark even when astronomical twilight is just ending in the morning. Atmospheric colors consist of deep dark blue toward the horizon, and completely black when facing west. Astronomical twilight really brings cityscape photos to life. The deep blue mixed with warm artificial lights from city buildings, streets, and cars produce nice contrasts. Arguably, this is the best time to photograph cityscapes, but this clearly depends what you’re attempting to capture. Images during all twilight phases and during sunrise require a tripod. The photo will be blurry, regardless if your lens has vibration reduction or image stabilization.
Nautical twilight is when the center of the sun is between 6° and 12° below the horizon. The primary color cast across the atmosphere is usually a deep blue hue with noticeable orange and yellow tones at the horizon due to the rising sun. Light will begin appearing quickly throughout this phase, and the blue sky will get begin to get brighter and paler. Details will become easier to distinguish but will lack most edge definition. Again, cityscape photographs are nicely produced during this phase. Most landscape photographs will be uninteresting during this phase because there is not enough available light. Silhouettes begin to look interesting, and get better in the next twilight phase.
When the sun finally rises, deep ruby red and dark pink colors splash all over the terrain. Shadows come alive and retain purple and blue hues due to scattered light. The contrasts of red and blue are at a pinnacle, and will arguably provide for the best landscape pictures. The mixture of colors and shadows helps distinguish form, shape, and texture, and these compositional elements should be utilized. The color of light is quickly changing from red to yellow, and you must react very fast if you decide to change composition or frame. As the sun continues to rise in the sky, colors shift from yellow to white. This is why the first hour of sunrise and sunset is called the “golden hour“, because red light shifts to gold. After the first hour of sunrise the color of light begins turning whiter and is not conducive to most landscape photography. The only circumstances that could create gorgeous photos in midday are during storms when the sun breaks through high clouds illuminating spots of land. Otherwise, forget about taking good landscape pictures – they will not be compelling.