Aperture

Once you get beyond being satisfied with the factory settings that came with your camera, the first concept you need to understand fully is aperture. Note that if you have a simple point and shoot camera, this information will be moot to you as the aperture is fixed and will only be adjusted by your camera and it can not be adjusted by you. But if your camera has a ton of little options like this:


then you can adjust your aperture and let the fun begin. Let's first define what aperture is. Aperture simply is the opening in your camera that adjusts the amount of light that hits the lens and in this case we can adjust the aperture ourselves instead of having the camera do all the work for us. We can use the much maligned pupil/camera analogy and you can think of the opening and closing of the aperture as the pupil of your camera. Just as the pupils in your eyes dilate to let more or less light in, so does the opening or aperture on your camera.

The diameter of the opening is called the f-stop, f-number or aperture value; different names for the same function and depending upon the setting it allows a certain amount of light to pass through the lens and onto your camera's sensor. As you can see in the above diagram, the smaller the f-stop number the larger the opening. To me logic would dictate that the larger the f-stop number the larger the opening, but it is exactly the opposite.

After you grasped the 'bigger is actually smaller' concept you are now ready to understand what all of this means to you:

By adjusting the aperture, you adjust the depth of field, which I will attempt to define at a later date. Simply put you have control over what elements in your picture will be in or out of focus. A rule of thumb to start with is the lower the f-stop (f-2.0) the blurrier the background or technically put: the shallower the depth of field. By the same token the higher the f-stop (f-14) the more in focus the background will be. If you want your entire shot to be in focus, your subject and all of the background, then you will want to use a higher f-stop. Got it? Good.

f/5.6


f/32
Jonquil flowers credit: Wikipedia.org

Additionally, the amount of light you allow will effect the outcome of your picture. Too much light and you picture will be overexposed, too little and your picture will be underexposed and dark. Selecting the right aperture is the first step in framing a perfectly exposed shot with the desired effect on the subject and background. Please note though that sometimes an overexposed or underexposed shot ends up being more visually pleasing to some than the 'perfect' shot. Beauty is in the eye of the beholder they say and that is true in photography as well.

Classic overexposure

Now you are probably wondering why on earth you need to know about aperture, f-stops and such. Control, friends. Control. It is all about control. Sure you could continue shooting in your factory settings mode and take perfectly fine pictures for the rest of your life. -Or- You can venture out a bit on the daring side and experiment. I can guarantee nothing but good will come from this and after using the f-stops a few times you will begin to grasp the concept and see the difference it makes in your photography. And when all else fails: Photoshop.

~ame