In photography we want to make clear what our subject is, and not have the viewer guess or have to resort to a caption or title.  One way of doing this is placing the subject in contrast with the background.  The photo to the right is an example of contrast.  Notice here we used color for contrast.  The bright blue stands out from the drab tan of the background.  By keeping the background defocused and neutral in color, it does not deter from the main subject, yet, it still provides context to the scene.


In this photo, we kept the elements simple.  The background is a blur of defocused bubbles.  The lack of other objects in the scene focuses our attention to the anemone in the foreground.

Notice this scene is relatively low in contrast.  The tonality of the anemone and the background are similar.  It is not necessary to apply all of the rules of composition in the same photograph.  Although rules can be used together, they also stand by themselves.

In this sample, even though there is not much contrast between the subject and background, the photo works because of the simplification.

The human mind is drawn to repetition.  As photographers, we can take advantage of this by utilizing patterns in our photographs, making them much more interesting.  Corals are colonial creatures, and as such are repetitious by nature.  The patterns inherent in these animals give us a great base from which to start our work.  In this example, the repetition of polyps directs our eyes to the details within each individual one.

Leading Lines
Leading lines, or diagonals, are strong tools in photography used to create a sense of dynamics to an otherwise static scene.  In this example, the subject (the reef tank) is in the center of the image, yet it does not appear static.  The closer end of the railing, on the right of the photo, leads our eyes into the room where we come across the tank.  It then continues past the tank to the master bedroom.  The use of leading lines here takes us through the hallway as though we were coming from one end and walking to the master bedroom, and viewing the tank along our trip.  It directs our attention to the subject, and gives us a path on which to continue our journey.

The use of diagonals with our subjects themselves or with lines in the photograph also adds dynamism to the photograph.  Straight horizontal lines appear static like the ground.  Similarly, straight vertical lines will appear as static as sticks stuck in the ground.  By sloping one of these lines, our minds pick up a sense of movement in the photograph.

When we print a photo, we often put it in a frame to display on our desk.  A good frame will enhance the photo and showcase it.  It serves to bring initial attention to the photo itself.  Similarly, we can use natural surroundings as a frame in our compositions.  Notice how this fish is framed by the cave in this rockwork.  This frame is not intrusive and gives a feel for the fish's environment.  Yet, it works like our desk frame, directing the eyes toward the subject itself.

A prop is anything in the photograph not part of the subject itself.  Correct usage of props creates interaction between the subject and its environment.  In this photo, the Anthelia sp. branch is used as a prop, giving the hermit a sense of calm; it is sitting under the shade of an old Anthelia sp. tree on a hot summer day.  Keep props simple so they do not deter from the subject itself.

As we already discussed, DOF is a powerful tool in directing attention through the photograph.  We can use this to isolate our subject.  There are several ways we can use DOF to this end and we will go through a couple with the samples below.
Defocused Background
By selectively defocusing the background we can bring the eyes to the subject in the foreground.  As in this subject, the shell in the background is easily identifiable, and places the hermit in a marine context.  For simple backgrounds, defocus lightly.  For complex and busy backgrounds, we want to defocus heavily so it becomes more of a consistent smear and does not deter from the subject.

Defocused Foreground
Here we defocused the foreground subject and focused on the background.  This brings our eyes to the brain coral. However, in this photo, we want interaction between the hermit and the brain, so we defocus the hermit's eyes only very slightly so it becomes part of the subject.  The large defocusing of the shell itself de-emphasizes it so it does not deter from the subject.

The low angle of this photo gives it a hermit's eye view of the world.  What we see is small insignificant hermit crawling up to the huge brain seeking wisdom.