Twilight or nightlight is one of my favorite times to take photographs. It makes for spectacular landscape and city skyline photography. I regularly head out and capture the Boston Skyline at twilight on days that I am not occupied hunting for nature photographs. The best time is 20 to 45 minutes after the sun has set. The optimum light does not last long. Because twilight is hard to predict I make sure to be on location prior to sunset. I often explore the location during the last light of the day and set up tripod and camera shortly after sunset for my twilight Photography Adventure. Ones twilight arrives I keep photographing while closing in on the optimum light. This approach requires sufficient battery power and flash card memory. The twilight effect also works on cloudy days and up to 30 plus seconds exposure times are not unusual.
Good light and happy photo making!