Controlling your aperture, and understanding it’s relationship with the exposure trifecta can be one of the most profound tools to manipulating the look of your photographs. As we discussed in the trifecta post, the aperture is a hole which allows light to pass through the lens and onto the sensor or film. By controlling the size of this hole, you control the amount of light passing through the lens. This is it’s primary function. Bright day, smaller hole. Dark cave, larger hole to allow as much light in as possible. The other feature of the aperture is its responsibility for your depth of field (DOF) or area in focus. If you look at the picture above, you can see on the bar top, that it is blurry in the foreground, sharp at the first wine glass, and then fades quickly back into the out of focus area. This was achieved by setting a large aperture, which when also getting the camera physically close to the subject in focus, it narrowed my DOF.