The word photography derives from the Greek photos ("light") and graphe ("drawing").
Light is really the most essential control that can effect the quality of your photography. If you have too much light then your images will be over exposed and if there is not enough light your images will be dark and underexposed. Since photography is basically "drawing with light", you should take some time to observe light and how it plays a role in your surrounding and in imagery.
If you have a DSLR and shoot in manual mode, then you already know that each adjustment made in manual mode is simply a lever used to control the amount of light that you let into your camera sensor. These controls; ISO, Shutter Speed, and Aperture, can also be used to apply other affects to your images but at the most basic level they are manipulations of light. If you adjust one of these dials, you have to make a counter adjustment to one of the other dials in order to balance the amount of light coming into the camera sensor.
When you are setting up a shot. Generally you will want the light in your image to be as even across your subject as possible and you will want enough ambient light so that your subject is lit well enough to see.
Below is a good example of lighting your image evenly. I took the image on the left when I was first starting out and as you can see the light is not even at all. There are shadows on the subjects face and quite a bit of blotchy shadows in the back ground caused by sun shinning though the trees in front of my subject. On the right, the light in the photo is much more even across the image. The light on the subject is even and nicely lighting her face. The sun is behind and to the left of the subject and is creating a nice hallow effect on her hair. This was shot later in the evening so it is a softer light than mid day. The light in the background is evenly lit as well eliminating distractions that will draw your attention away from the subject.
Can you see the difference and how the lighting on the subject makes such a big impact?
The amount of light available when you are taking a photo can have a big impact on your images. Below is a good illustration of different exposures. On the far left, the faces are overexposed and you start to lose texture and detail in the faces. The middle image has a much better exposure. You can see the faces well and they still have enough contrast on that you can see the dimension and texture plus details in the eyes. On the right, the image was taken at a concert in a dark stadium. It is underexposed and it is looking a bit grainy. There just wasn't enough ambient light to create a nice dynamic photo. The contrasts are starting to run together and again you start to loose details in the photo.
Overexposed Good Underexposed
Tip: You can move to a shaded area to get a more even light source and decrease the amount of ambient light if it is too bright. To get more light move closer to a window or the edge of the shade line in order to access more light for your photos.
Open shade is a great place to find even and soft light. Open shade is an area where there is available shade but you still have access to the open sky. A good example would be an alleyway or tree line where there is no direct sun hitting the subject but you can look up and still see the sky above you.
That is all I have for you today. Let me know your photography questions. If I don't know the answer, I will look it up and try to answer it here on the blog!