You can do photography with even the simplest of cameras, but the principles that I’d like to explain are for people who want to learn to use a DSLR camera, a micro four-thirds camera, or at least a camera that allows the photographer to adjust the shutter speed, aperture, and ISO. Even some pocket cameras have this functionality. What is shutter speed, aperture, and ISO ?
SHUTTER SPEED
shutter speed is ‘the amount of time that the shutter is open’. In film photography it was the length of time that the film was exposed to the scene you’re photographing and similarly in digital photography shutter speed is the length of time that your image sensor ‘sees’ the scene you’re attempting to capture.
Shutter speed is measured in seconds – or in most cases fractions of seconds. The bigger the denominator the faster the speed. In most cases you’ll probably be using shutter speeds of 1/60th of a second or faster. This is because anything slower than this is very difficult to use without getting camera shake. Camera shake is when your camera is moving while the shutter is open and results in blur in your photos.
If you’re using a slow shutter speed (anything slower than 1/60) you will need to either use a tripod or some some type of image stabilization
APERTURE
Simply put, aperture is a hole within a lens, through which light travels into the camera body. It is easier to understand the concept if you just think about our eyes. Every camera that we know of today is designed like human eyes. The cornea in our eyes is like the front element of a lens – it gathers all external light, then bends it and passes it to the iris. Depending on the amount of light, the iris can either expand or shrink, controlling the size of the pupil, which is a hole that lets the light pass further into the eye. The pupil is essentially what we refer to as aperture in photography. The amount of light that enters the retina (which works just like the camera sensor), is limited to the size of the pupil – the larger the pupil, the more light enters the retina.
So, the easiest way to remember aperture, is by associating it with your pupil. Large pupil size equals large aperture, while small pupil size equals small aperture.
One important thing to remember here, the size of the aperture has a direct impact on the depth of field, which is the area of the image that appears sharp. A large f-number such as f/32, (which means a smaller aperture) will bring all foreground and background objects in focus, while a small f-number such as f/1.4 will isolate the foreground from the background by making the foreground objects sharp and the background blurry.
ISO
A high ISO such as ISO 1,600 will produce a brighter picture than a lower ISO such as ISO 100. The drawback to increasing the ISO is that it makes the picture noisier. Digital noise is apparent when a photo looks grainy. Have you ever taken a picture at night with your cell phone or your pocket camera, and noticed that it looks really grainy? That is because the camera tried to compensate for the dark scene by choosing a high ISO, which causes more grain.
