The medium of the photographer's art is light. Light enters the lens of the camera and reacts with the film or digital sensor to create an image on the film or digital sensor. When shooting in a situation without enough light, there are several possible solutions to create a good image, including changing your camera settings, adding artificial light or changing the sensitivity of your image media.
Shutter Speed and Aperture
Shutter speed and aperture are important in night photography, whether it is film or digital. These basic camera settings determine how long the lens stays open and how wide the lens opens. In lighted situations, these settings can give greater artistic control; in low-light settings such as night photography, they can allow more light to fall on the sensor.
Shutter speed determines how long the shutter remains open and the image sensor exposed to light. In night photography, a long shutter speed may be necessary to capture an image because there is little available light to fall on the sensor. The drawback to increasing the shutter speed is that it will not capture movement very well--any motion while the image media is exposed will appear blurred.
Aperture is a measure of how wide the lens opens. A lower aperture number denotes a wider aperture opening, allowing more light to fall on the lens. Aperture may be limited by the lens you are using or by your digital camera's settings. Opening the aperture widely to allow light in is useful in night photography, but it will decrease the depth of field, meaning less of the photo will be in focus.
Artificial Light
Adding artificial light, such as a flash, will allow for more light to be reflected back into the lens at the time of exposure. Using a flash at night may create harsh shadows; if you have an adjustable flash unit, try aiming it away from the subject or using a bounce card to reflect light onto the subject. This softens the flash and creates a more natural image.
Artificial light does not have to come from photography equipment. Headlights, streetlights or any other ambient or portable light source may be used.
ISO and Sensitivity
ISO is short for International Organization for Standardization. In a photography context, ISO is used to refer to a film or digital sensor's sensitivity to light, also called the "speed." Very low ISO numbers indicate that the sensor is less sensitive to light and is suitable for bright light situations, such as heavy studio lighting. A very high ISO indicates the sensor is very sensitive to light and will be good for low-light situations such as night photography.
Changing the sensor's ISO is a good idea if you cannot add artificial light and you do not want to compromise on your shutter speed and aperture settings. The drawback to high ISO settings is that there is more "grain" to the image. The resulting image will have more pixels calculated by algorithm in the camera and fewer based on the actual image. This can result in blotchy images with poor quality. ISO is a useful tool for digital night photography, especially when it is balanced in combination with artificial light and your camera settings.
Tags: night photography, camera settings, film digital, digital sensor, film digital sensor, light fall
