DSLR Basics

In digital photography, exposure is the unit of measurement for the total amount of light permitted to reach the electronic sensor during the process of taking a photograph. The two main controls your digital camera uses to control exposure are the shutter speed and aperture.

Shutter Speed

Shutter speed, also known as “exposure time”, stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it can help to freeze action completely, as seen in the above photo of the dolphin. If the shutter speed is slow, it can create an effect called “motion blur”, where moving objects appear blurred along the direction of the motion. This effect is used quite a bit in advertisements of cars and motorbikes, where a sense of speed and motion is communicated to the viewer by intentionally blurring the moving wheels.

Aperture

Aperture is a circular opening (somewhat) in our lens that is adjustable from a very small circle to almost as large as the lens itself. We adjust it to let more or less light hit the digital sensor or film. Think of window blinds as your aperture, and the wall in your room opposite the blinds is your sensor or film. As we open the blinds, more light comes through and we can see the wall behind us get brighter and brighter