Photography works on the principle of recording on light-sensitive material an image created by light reflected off the subject. This principle works well enough in daylight, but once night falls, film or digital sensors---charge-coupled devices used in digital cameras---has more difficulty recording the much lower light reflected. There are some ways around this, however.
The Basics
Photographing night scenes without the use of flash can be tricky, but there are some material considerations that will make it doable. First, get high-speed film in the range of 800 ISO or higher. Digital cameras usually have a setting to simulate high ISO speeds, some going up to 3,200 ISO. The faster the film, the more light it will capture. The downside is that in film or digital, the higher the ISO, the grainier the image. Second, get a low-light lens. A normal lens---one that records the same size and perspective the human eye sees---usually has a wide-open aperture of F/1.8. Getting an F/1.4 lens will increase the light coming into the camera. The smaller the number, the more light is focused to the film or CCD. When shooting at night, the more natural light you can gather, the less you will need a flash.
Night Light
Use a tripod and slow shutter speeds for subjects that aren't moving, aren't moving much or that you want the motion recorded as streaks of light. Most 35 mm-style film and digital cameras and medium-format cameras have slow shutter speeds. Shooting at anything less than 1/30th of a second requires placing the camera on a tripod or some other stationary object to avoid camera shake. Many cameras also have a "B" setting which allows the photographer to press the shutter button once to open the shutter and a second time to close it. Using a remote control or shutter release cord will allow you to trip the shutter without moving the camera. Use this technique to photograph the night sky or even a backyard, as the long exposure will gather in a great deal of light over time.
With a Flash
You can use flash units or photographic lights to capture night scenes, but they will change the overall look of the image. Don't use an on-camera flash to photograph people at night because it will cause red eye. Take the flash off the camera and hold it high and point down, bounce the flash off trees or structures or hold the flash to the side to light indirectly.
Use lower-wattage bulbs in photographic lights to soften the glare full-wattage lights produce. You also can turn the lights slightly away from the subjects to get less light on them.
Tags: film digital, aren moving, have setting, light reflected, more light, night scenes