Night Photography

refers to photographs taken outdoors between dusk and dawn. Night photographers generally have a choice between using artificial light or using a long exposure, exposing the scene for seconds or even minutes, in order to give the film enough time to capture a usable image, and to compensate for reciprocity failure. With the progress of high-speed films, higher-sensitivity digital image sensors, wide-aperture lenses, and the ever-greater power of urban lights, night photography is increasingly possible using available light.

HISTORIES
In the early 1900s, a few notable photographers, Alfred Stieglitz and William Fraser, began working at night. The first photographers known to have produced large bodies of work at night were Brassai and Bill Brandt. In 1932, Brassai published Paris de Nuit, a book of black-and-white photographs of the streets of Paris at night. During World War II, British photographer Brandt took advantage of the black-out conditions to photograph the streets of London by moonlight.
In the late 1970s, Steve Harper taught the first college-level course on night photography at the Academy of Art College in San Francisco. The legacy of this program has led to San Francisco becoming a center of night photography.
By the 1990s, British-born photographer Michael Kenna had established himself as the most commercially successful night photographer. His black-and-white landscapes were most often set between dusk and dawn in locations that included San Francisco, Japan, France, and England. Some of his most memorable projects depict the Ford Motor Company's Rogue River plant, the Ratcliffe-on-Soar Power Station in northern England, and many of the Nazi concentration camps scattered across Germany, France, Belgium, Poland and Austria.
During the beginning of the 21st century, the popularity of digital cameras made it much easier for beginning photographers to understand the complexities of photographing at night. Today, there are hundreds of websites dedicated to night photography.
For a more complete history of night photography, refer to Lance Keimig's A History of Night Photography.
Subjects
Astronomical objects - moon, stars, planets, etc. See astrophotography.
Streets, with or without cars
Abandoned buildings and artificial structures lit only by moonlight
City skylines
Factories and industrial areas, particularly those that are brightly lit and emitting smoke or vapour
Fireworks
Nightlife or rock concerts
Bodies of water (lakes, rivers, canals, etc) reflecting moonlight or city lights
Thunderstorms
Amusement rides
Technique and equipment
The length of a night exposure causes the lights on moving cars to streak across the image
The following techniques and equipment are generally used in night photography.
A tripod is usually necessary due to the long exposure times. Alternatively, the camera may be placed on a steady, flat object e.g a table or chair, low wall, window sill, etc.
A shutter release cable or self timer is almost always used to prevent camera shake when the shutter is released.
Manual focus, since autofocus systems usually operate poorly in low light conditions. Newer digital cameras incorporate a Live View mode which often allows very accurate manual focusing.
Long exposure multiple flash photographic technique
The long exposure multiple flash technique is a method of night or low light photography which use a mobile flash unit to expose various parts of a building or interior using a long exposure time.

Long exposure means that the shutter of the camera is kept open for longer, allowing more light to be exposed to the images sensor or film of the camera. This causes the photograph to be lighter, and is good for night and dark photos.
This technique is often combined with using coloured gels in front of the flash unit to provide different colours in order to illuminate the subject in different ways. It is also common to flash the unit several times during the exposure while swapping the colours of the gels around to mix colours on the final photo. This requires some skill and a lot of imagination since it is not possible to see how the effects will turn out until the exposure is complete. By using this technique, the photographer can illuminate specific parts of the subject in different colours creating shadows in ways which would not normally be possible.
(copy by wikipedia)