. By: Richard Schneider

The use of light in a photograph can be the deciding factor of whether that picture will be spectacular or terrible. When you use your camera to automatically choose aperture and shutter speed, what your camera is actually doing is using the built in light meter and measuring how much light is being reflected to the camera.
But that doesn't mean that’s all there is to it. You should also think about the angle of the light entering the frame, what kind of shadows you want, and whether you want to use fill-in-flash (using flash to light the subject if you have a really bright background). If you are shooting at night you can create all sorts of cool effects like lights in motion, pictures with moonlight, or silhouettes. The following are just some examples of all the possibilities.
Angle of Light
The angle of light should be taken into careful consideration whenever you feel like you want to create a specific effect. Shadows can be very powerful when cast over half of someone's face. When you are deciding which angle you would prefer to have the light coming from you are indirectly deciding where the shadows will be cast. The angle of light can be used to show texture if it is coming from the side because the shadows create the effect of more depth. It can add detail and mystery to someone’s face if you choose to keep half of their face in the shadows. The most common light usage mistake that people make when they are taking portrait pictures is having the light coming directly from the back when they don’t intend to create a silhouette. This usually results in having the subject’s face just very dark and the background overexposed.
Light Rays Effect
The effect of rays of light indoors and outdoors can be very spectacular. A brilliant part of some great photographs is the ability to actually see rays of light in a photo. Whether it is in the setting of a brilliant sunset, light pouring through a window or light from artificial lights almost all kinds have the potential to look amazing. Usually the only way to obtain something like this is a narrow aperture (high f/stop) and a very slow shutter speed. I have found rays of light to be very nice in architectural photography in the form of light streaming through windows or spaces.
Silhouettes
Silhouettes are another interesting example of strategic light use. The way to create a silhouette is to have significantly brighter light coming from behind the subject. In doing this it is important to take your camera light reading off of the background instead of the subject in order for the camera to adjust for an exposure based on the backlight. If you do this the subject will be successfully underexposed and the background should hopefully have a well-balanced exposure. You can do this for any kind of subject including people, animals, landscapes and impressive cityscapes.
Scarce Light in the Darkness
Photography at night is completely different than photography in the day. At night there is most likely not enough light to handhold the camera if you are going to take a well-exposed photo (without flash). A tripod is very necessary and I always use a tripod when I am shooting at night to take away the risk of blur from hand shakiness. If you keep experimenting with different ways of using light you will find that you can get very interesting results. One favorite location of night photographers is on the roadside of a busy street. With a long shutter speed the photographer can use the car lights to make streams of light across the frame. The longer the exposure, the more fascinating the results with light most of the time.
Try This Technique to Make a Copy of Someone
Set the shutter speed for somewhere around 30 seconds, set the camera on a tripod and set the self-timer so you do not have to press the shutter button. Someone needs to stand next to the camera with a flashlight and someone else needs to be the subject of the photo in front of the camera. The subject then stands in one place while the flashlight is pointed at him and moved in an up and down motion. After around 15 seconds the flashlight is turned off and the subject is told to move to his left. Then the flashlight is pointed at him again and moved up and down until the camera finishes the exposure. If you do this successfully you can create the same person twice in one frame.
Conclusion
The use of light is a very essential practice to master if you are going to be a successful photographer. When a digital camera takes a photo its sensor is essentially just collecting all the light from the scene that is reflected in through the lens. It is your job simply to figure out where you would like the light to be coming from and how long the sensor should be exposed to the light in order to create a sufficient exposure.