Composition is everything in a photograph, (well that and contrast, story, color, exposure and a few other minor things). Ok so there is a few things that make up a good photograph but for this entry we are going to talk about composition... where do things sit in the image? what makes for an interesting composition. To understand what we find visually interesting (or what we will look at) we need to understand a bit about how our minds work. By design we like to identify, sort, classify and label things. We do it every waking minute and probably a fair amount during sleep. This is a very useful process to establish if something is dangerous for example. A down side of this function is that we humans tend to dismiss the known without much consideration. For example if you saw an apple every day and had never seen a pineapple, which would you look at longer if presented with both items? Because we are tuned to look for things that "stick out" or are different, we are quicker to dismiss those items that are symmetrical as being correct or safe. Items that are random, off-balance or asymmetrical cause us to look and think about them longer. This is the first challenge of a visual: how do I capture my viewer long enough that they realize there is something worth looking at? Most hobby photographers have a tendency to place the subject in the center of the frame (because that is where the auto focus spot is) but often times that is not the best place for the subject. If there is action or direction in the image (think of a boy running from left to right of your view) it is nearly always better to place the subject to the side of center. In our running example if the boy were placed on the left edge of the photo he has space to run into, if he is on the right we create tension because he is running into the edge quickly. That tension may be part of your story if he is being chased by something. If his pursuer is something harmful like a tiger this tension can be very stressful for the viewer, if it is something innocent like a bunny the tension adds comedy. In the following example you will note the couple is not placed in the center.
In this photo "Married on the midway" we used the leading line of the railing to lead the eye into the scene. The vertical lines of the carousel stop the eye from running out of the image with the railing. We achieve additional focus on the couple from the horse that is looking in their direction. The dark area on the right helps to pull the eye back into the scene. We visually wander down the boardwalk to see what is going on but the soft focus tells the mind "nothing here to see, move along".
That same image cropped with the couple in the center is still nice but would hold the viewers attention for less than half the time.
