The next most common use for the shutter priority mode is to convey motion in one or more objects within a scene. By forcing the shutter speed to slow down, you will introduce motion blur, which can be very effective at conveying motion or speed. As the shutter speed is forced slower, the camera will compensate by decreasing the aperture (increasing f-stop number), which also increases the depth of field. If this side-effect is not desired, then you can use a neutral-density filter to reduce the amount of light reaching the sensor instead of having the camera pick a smaller aperture. You might also consider using a polarizing filter to reduce the incoming light by about 2 stops, if the polarizing effect is not undesirable (it can cause streaking in glass and plaster; and occasionally change the appearance of some colors). Experimentation is normal when using this technique as you need to find a balance between freezing those elements that you want in sharp focus, yet capturing the right amount of blur from moving objects. The amount of motion blur will change depending on your shutter speed, so you need to experiment to determine the best amount of motion blur to fit your vision. In most cases you will want to have your camera on a tripod so that movement of the camera won’t be a factor. If you don’t have a tripod, then rest the camera on some solid object such as a table or bench, or even on the ground while taking the picture. Whenever you use a tripod or otherwise stabilize your camera to take a picture, turn off your image stabilization or vibration reduction (if you have it). Since the camera is presumably stable, this feature may actually introduce a small amount of lens movement as the camera tries to remove movement that isn’t there.
- Set up a sprinkler so that water drops fall on some flowers in direct sunlight. Focus on the flowers for a scene of flowers in the rain. Set your camera to 1/60 sec to get the slightly blurred water drops appearing as rain.
- Focus on a car, bus, or train – any moving vehicle, but it should not be moving directly toward or away from you. While holding the camera still, adjust the shutter speed to see how it affects the motion-blur of the moving object, while keeping slow or stationary objects crisply in focus.
- Focus on a person holding a ball. As the person bounces the ball, try slowing the shutter speed and taking a picture at different points in the bounce – when they first drop or throw the ball, when the ball hits the floor, as it is bouncing back up – to see if you can get a picture where the person is sharp, but the ball is blurred.