A motion blur effect works really well in sports photography, giving your viewer a sense of speed and action. It is also a great standalone photographic technique for dramatizing certain kinds of scenes. You can capture the speed of a running cheetah or the streaks of light coming from speeding cars moving through the city at night. Wherever something is moving, you can get in touch with its motion by using this technique.
Slowing the shutter speed
While there are many ways to create a motion blur effect, the best way to start is by slowing down your shutter speed. When the shutter is open longer, the subject has more time to move across the frame and establish some kind of blur. Think of it this way. How far does your hand move in front of your eyes in 1/500th of a second? Okay, that’s a tough one to answer. But for contrast, ask yourself the following: How far does your hand move in front of your eyes in 3 seconds? Obviously, it’s much further. The same rule applies for cameras.
Consider your exposure
Here is another factor to consider. Every scene has different light levels. In the middle of the day with the sun shining at its peak, a lot of light will be entering your camera. The problem with slower shutter speeds is that they let more light in every time you take a picture. When it is bright and sunny outside, this can quickly lead to exceedingly bright pictures with washed out colors. In other words, it leads to overexposure. To compensate for this, you either have to close the aperture more (use a higher f-stop number), adjust ISO to a lower number, or place a light blocking filter in front of your lens.
Try shutter priority mode
All digital SLR cameras (and most Point and Shoot cameras) have a shutter priority mode that can simplify the process of slowing down the shutter speed. In shutter priority mode, you need only tell the camera the shutter speed you are looking for, and it will automatically pick an aperture and ISO for the scene you are photographing. While shutter priority mode works in a wide variety of situations, it isn’t a fix-all for every photographic scene. Your camera may have a great light metering system to help it pick the right aperture and ISO settings, or it might not. Always double check your photos after you take them to make sure they are being exposed correctly.
Getting the right blurring effect
So how slow should your shutter speed be? It all depends on the effect you are looking for. The longer you leave the shutter open, the more motion blur you will have. Images will begin to blur slightly at any shutter speed below 1/500th of a second. When you get near the 1/15th of a second range, blur will become very noticeable.
Panning, an easy way to create a sense of motion
One easy way to create a motion blur effect is to follow your subject with your camera while you are taking the photo. This is known as panning, and it creates a really cool effect. If you have picked your shutter speed correctly, and you can manage to follow your subject fast enough, your subject will appear still in the photo while everything else around it is blurred in the direction of the subject’s motion.
For everything else, a tripod is essential
All other motion blur photographs require the use of a tripod. There is simply no getting around this. When you use a slower shutter speed, everything in the frame can become blurred unless you are holding the camera perfectly still. These are known as camera shake issues. The tripod keeps the camera still while the subject moves throughout the frame, blurring only the subject while keeping the background crisp and clean. In the image to the right, the water is blurred but the background is sharp. Without a tripod, the longer shutter speed needed to make the water blur would also have caused the background to blur because of a small amount of camera shake.
One more technique
Once you have mastered all of the above techniques, try using a flash combined with a slow shutter speed. The light from the flash bounces off of your subject, making it crisp while everything around it blurs throughout the duration of the exposure. It’s perfect for parties, and very fun. You’ll be amazed at what you can do when you get creative with motion blur.