If photography is all about seeing things, then better photography is about learning how to see things differently. I do not mean this in a philosophical sense, even though if you want to take truly great images they should have some kind of idea or philosophy behind them.
No, I am talking very much about seeing things differently in a mechanical sense. Placing your eyeballs in a different place, or using the camera, as a machine, to change the way we perceive.
Your eyes are probably located somewhere between five and six feet off the ground. This is a trait that you share with almost all of humanity. It is the viewpoint that almost everyone shares; we are used to walking around and seeing things from eye-level. Therefore, this point of view is familiar, and, frankly, uninteresting.
You can begin to see things differently by physically putting yourself in a different location. Lie down on the floor on your back, and look up. Take a picture. Lie down on the floor on your stomach, so that you are looking up, not down, at your three-year-old. Take a picture.
Climb up to the second floor of your house and take a picture of the lawn party or block party out the window, rather than trying to get a shot of the crowd from within the crown itself. Take a balloon or helicopter ride and photograph the landscape looking down, so that there is no horizon.
Change where your eyeballs are. That automatically changes where your camera is.
To add another angle, so to speak, to how you see, use different focal lengths. In lay terms, this means zooming in or out. But there is more to it than that. When you change focal length, you don’t just change how close of far away you seem. You also change the angle of view, and the amount of compression of the images.
Angle of view is how wide, side-to-side, the frame is. On a full-frame 35mm system, a “normal” focal length is about 43mm. Aside from the fact that almost no one makes lenses of this focal length (Canon does make a 40mm that I hear is a dandy), if you put this on your camera, and look through it, you will see almost no change in what you are seeing. A popular lens is the 50mm, which will capture the scene at about the same magnification that we see it with our eyes, but it will not be quite as wide. A 35mm lens will capture how wide we see, but the image will be a bit smaller.
Let’s say, though, that we are in a scene where we want to capture a lot. We need a “wide angle” lens, maybe a 24mm, or an even lower number. This will capture more of the scene by widening the angle of view. This has the effect of making lines and angles more dramatic, and accentuating the distances between people and things. Someone or something in the foreground will appear large, and someone just several feet away will appear much smaller. Wide lenses also increase depth of field, so more of your image will tend to be in focus.
On the other end of the spectrum is a telephoto lens, which you might say zooms in by narrowing the angle of view. You will get a tighter shot, and angles and perspective lines will be minimized. With telephoto lenses, you also see a good-looking phenomenon called compression, which is when things that are separated by some distance look as if they are closer together. You see this on TV sports coverage all the time. It is also a wonderful thing in portrait photography, both with individuals (it makes noses look smaller, for example), and groups (it looks as if the back row is right there with the front row). Also, with telephoto lenses, your depth of field decreases, and you can easily get a nice blurry background that helps the subject stand out.
Homework: Grab your camera. Sit on the floor. Climb a ladder. Zoom out. Zoom in.