Often photography is about freezing the action. But increasing the time the shutter is open can also create atmospheric images.
Pontneddfachan, © Gordon Stirrat 2011, Canon EOS 30D
So how do you create an image that makes the water blur, giving this dreamlike appearance? The technique is to use a slow shutter speed; the longer the exposure, the smoother the water appears.
Move the Mode Dial on the top right of your EOS onto Tv. Tv (Shutter-priority AE) lets you select the shutter speed for your picture whilst the camera chooses the correct aperture setting so that you still get the right exposure. Use the Main Dial just behind the Shutter Button to select your shutter speed. The amount of blur will depend on the speed of the subject and the length of the exposure.
You will need to experiment with the shutter speed a little to get effective blur of the water as it depends on how quickly the water is flowing. A good shutter speed to start with is 1/2 second. Often exposures of 30 seconds are used to give a really smooth finish. A useful tip is to select a lower ISO Speed (the sensitivity of image sensor on your camera to light), which will let you choose slower shutter speeds.
Although you are blurring the water, it is important that the rest of your photo is sharp, so you need to make sure that your camera is steady and doesn't move. A tripod is best for this as it allows you to be more flexible with location; at the very least you will need to find somewhere to rest your camera.
Long Exposure Noise Reduction
Digital images can show increased ‘noise’ (grain effect) with long shutter speeds. You can reduce this by switching on ‘Long Exposure Noise Reduction’ available on many EOS models in the Custom Functions within the <MENU> settings. Check your Instruction Manual (downloadable here) as exact operation varies from EOS to EOS.
However, it takes the camera as long to do save your image using this feature as the actual exposure, so a 15 second exposure will take 30 seconds to be saved and for the result to be shown on your camera’s LCD screen.