Today's Photo Skill: Controllers of the Light - Aperture

So the aperture is the opening that lets light onto the camera's sensor and the size of the aperture determines the amount of light. Aperture is measured in f stops and the smaller the f-stop the larger the opening. So it stands to reason that in darker conditions a bigger opening would help the exposure by bringing in more light and conversely, in a bright situation, a smaller aperture would help to keep the exposure from being blown out by restricting the light. All true.

If the aperture size only impacted light it would be easy to learn. However, aperature also creates depth of field (DOF) and so it impacts your composition as well. Our discussion of exposure controllers now gets a bit complicated by DOF. The larger the aperture the shallower the DOF. This can be a very cool and useful feature when you want your subject to be in focus and the background to be blurred or even to create bokeh (pronounced "bouquet") which is soft "blobs" of light. This is not so good when the shallow DOF blurs the subjects ears, keeping only part of the face in focus. 

When deciding on an aperture to shoot, DOF must be a consideration. What to do if you have a large group of people and not much light? A big aperture might just blur some of the subjects in the back row and a small aperture would get them all in focus but too dark... That's where the other 3 controllers come into play!

Hands on for this week, put your camera into A mode. Set the biggest aperture you have (the smallest number for the f-stop) and take a picture of a relatively close up subject. Then set the aperture to be the very smallest and take the same picture. Do this a few times with different subjects. Note what happens to the shutter speed each time you change. Look at the images and see the difference in the blurring of the background.

Next up is Shutter Speed.

Shoot lots and dream big!