 Photography is all about capturing light. A camera captures the light that enters through the lens using a sensor to digitise the information and create a photograph. Digital SLR cameras have a whole range of features, lenses and accessories to change and optimise the light that goes into the camera. This video will look at how shutter speeds can alter the amount of light that enters the lens. The vast array of dials and settings you get on a good camera can be quite daunting at first. In fact, most people start on the green square setting that gives almost full automatic function to the camera. However, to get the best out of a camera and be truly creative, it's best to take some time and understand how to use some of the manual functions. This will greatly affect the outcome of a photo to suit whatever your creative needs. To switch your camera to manual mode, simply turn the dial to M. The speed at which you set the shutter not only affects the amount of light that goes into the camera but can also be used to make some exciting and cool effects. So, what happens when you change the shutter speed? Firstly, even a small change in the shutter speed can have a big effect on the picture. The faster the shutter speed, the less light is captured, making the image appear slightly darker. The slower the shutter speed, the more light goes in making it lighter. To adjust the shutter speed on your Canon camera, you move this dial here. You'll also need to change your ISO to manual, as by default that's set to automatic. If you need help on this, check out our other video on ISO. In normal daylight, approximately 1 over 1 2 5, which denotes 125th of a second, is a good starting point to getting the right balance. If the image is too bright, you will need to make the shutter speed slightly faster. Around 1 over 250 should result in less light getting in. Conversely, if your photo is too dark, slow the shutter speed down to let more light in. If you have a really fast shutter speed, 1 800th or higher, you can freeze moving objects, which is great for effects such as this. If you slow the shutter speed right down, you'll find you get a blurred image. However, by carefully controlling the speed, you can gain access to some great effects. For example, if your subject is moving and you want to capture some of that movement, a shutter speed of 1 5th of a second will give just enough blur to get that effect. Note that any speed below 1 60th will result in the camera shaking as it picks up the movement of the photographer's hand, holding the camera. To counteract this, you need to keep the camera steady, either with a tripod or by putting the camera on something flat and solid. As a rule of thumb, 1 over the focal length of your lens is a good starting point. For example, if you have a 300mm lens, 1 over 300mm will ensure you get a sharp image. There are three fundamental factors that are important for every photographer to understand. All of which affect the amount of light that goes into the camera and how the camera performs. These are 1, the aperture, 2, the ISO number and 3, the shutter speed. They all work in tandem with each other and are therefore often referred to as the exposure triangle. To make experimenting with shutter speed easier, Shutter Priority Mode will give you the creative freedom with shutter speed whilst the camera helps you automatically with other settings, such as aperture and ISO. Simply turn the dial to TV. We recommend you take a look at our separate videos available for aperture and ISO to go into more detail.