Term: Motion Blur
Description: In photography, motion blur is an artistic technique that captures the movement of a subject in an image by using a slow shutter speed. With the camera’s shutter open longer, any movement within the scene gets blurry with time. It can also be done by moving or panning the camera while the shutter is open, causing anything not in focus to become blurred. This can create a dreamy effect in which objects appear to glide across the image, making it aesthetically pleasing and full of character. Motion blur is often used in sports photography or any situation where fast-moving subjects are involved, as it captures their speed and agility in detail. It’s also used as an effective way to communicate photographic storytelling by conveying action on a still image. In short, motion blur is a useful techniques for adding impact and drama to a picture.
Motion Blur and Slow Shutter Speed Tutorial
Using slow shutter speed is also known as motion blur, long exposure, or shutter drag. Each of these terms essentially means the same thing. Adding motion to a still photography can turn a regular photo into one that is dynamic and full of energy. Alternatively, you can create abstract motion and add a slow shutter speed surreal mood to your images. Some examples that you may be familiar with include a speeding train passing by a train station or a trail of lights from the cars at night. The creative possibilities with using slow shutter speed are endless. To help you achieve the most out of your slow shutter speed images, here are some guidelines that you can follow, as well as some common scenarios to use them in.
What Affects Motion Blur
If you read the previous guide on Freezing Motion with High Shutter Speed, you may recall that there are several factors that affect how fast of a shutter speed you need to freeze motion. These same factors also apply to how much blur shows up when you use a slow shutter speed.
Speed and direction of the moving subject
The speed and direction of the moving subject affects how much of a motion blur will be created. The faster the subject is moving, the more blur is created. Additionally, a subject that is moving side to side will also show more blur than a subject that is only moving towards or away from the camera.
If this Ferris Wheel is spinning fast, you may only need 5 seconds to achieve this look. But if it is spinning slowly, you may need to slow your shutter speed down to 30 seconds to 1 minute in order to get the same look.
The distance between you and the subject
The closer the subject is to you, the more pronounced the motion is going to be. So if you capture the Ferris Wheel 10 feet away, it will look more blurry than if you were to take it 100 feet away.
Focal Length of Lens
Similarly, if you were to shoot that Ferris Wheel at 100 feet away with a 200mm lens, the Ferris Wheel will be more blurred compared to if you were to shoot it with a 35mm lens from the same distance. This is because the subject will be moving through a larger portion of your frame.
General Guidelines for Shooting with Slow Shutter Speed
How much blur?
Unlike freezing motion, there is a lot of range when it comes to showing motion in your image. Do you want just a little blur to imply movement or do you want a long abstract trail of motion or light trail? Showing just some motion blur can be achieved with as high of 1/100th second shutter speed for fast moving subjects like cars, while just showing the taillight trail may require 10 seconds shutter speed.
Trial and error
Sometimes it will come down to trial and error when it comes to figuring out just how much shutter speed you will need for the amount of motion blur that you are looking for. Luckily, with the advent of digital cameras and instant LCD review, all you have to do is take a look at the back of your screen and see if you need a longer or shorter shutter speed.
Minimize blur from camera shake
Although you want to introduce motion blur with slow shutter speed, what you don’t want to have is camera blur caused by any movement of your camera.
Ideally, if you are shooting with a slow shutter speed, you want to secure your camera on either a tripod or on top of a stationary object like a table in order to keep your camera still.
If you have to shoot handheld, however, the rule of thumb is that when you use a shutter speed number that is lower than your lens’ focal length number, you will start to introduce camera blur into the photo. An example of this would be if you were to shoot 1/30th second shutter speed while using an 85mm prime lens. One way to help minimize camera blur is to use your camera or lens’s image stabilization system. You want to also make sure that you are using the proper camera holding technique. We have an excellent article that can help you improve the way you hold your camera.
Use Neutral Density (ND) filter when needed
When you slow down your shutter speed, you are also allowing more time for light to hit your sensor, which in turn increases the image exposure. In order to get a proper exposure, you will have to close down your aperture. But in some cases, like a bright sunny day, you may not be able to close your aperture down enough to get a balanced exposure for a really slow shutter speed. Other times, you may want to shoot with a more wide open aperture while still using a slow shutter speed.
So for these cases, you can attach a filter on your lens called the Neutral Density (ND) filter. The ND filter is essentially a darkened piece of semi-opaque hard disc or square that acts like a pair of sunglasses on your lens to cut down the amount of light hitting your sensor. Because less light is coming in at any given time, you can slow down your shutter speed on a sunny day.
Creative Slow Shutter Speed Scenarios
Subject in motion
Although you can always freeze a subject, when you slow down your shutter speed to add motion blur, you introduce an added dynamic dimension for that subject. For example, this shot of a spinning wheel would look boring and lifeless if it wasn’t for the spinning motion blur.
Stationary subject in moving environment
On the flip side, you can also shoot a stationary subject in a moving environment. The long shutter speed will blur the movement of the surrounding environment, while the subject remains in focus. This technique makes the stationary subject stand out in the image. The amount of shutter speed you need will depend on how much blur you want in your environment.
Movement in Environment by Lin and Jirsa Photography
Shooting at night in an urban setting and allowing the moving car lights to streak is another popular way to use slow shutter speed. Depending on the speed of the moving vehicles and how far away you are from them, you can use ½ second to 10 seconds for your shutter speed. Just be sure to use a tripod when shooting this type of photos.
Misty waterfalls and bodies of water
You can turn moving water from waterfalls or in the ocean or a lake into a smooth, silky, ethereal flow simply by slowing down your shutter speed to around ½ sec or more. I love the artistic way that you can play with long exposure and water. For a more in-depth look on this type of photography, you can check out our article on using long exposures to achieve glassy water.
Out of all the ways you can shoot with slow shutter speed, panning is probably the one that takes the most practice and technique. This is because while you want to blur the background, you want to retain a reasonable degree of sharpness with your subject.
The required minimum shutter speed will depend on the subject’s speed and direction, the subject-to-camera proximity, and the focal length of your lens.
The trick in shooting panning shot is that you don’t want to hit the shutter button right when you just start to pan. Get yourself moving in a smooth motion as you track your subject then take the shot. Additionally, have a smooth follow-through as you finish out the shot because any stopping or jerky movement may get recorded.
Here is the technique that I use to get good panning shots. If you know that the subject is moving across the frame from right-to-left like in this race car example above, stand with your body facing the track with your feet parallel to the track. Twist your upper body to the right and have your camera prepped and ready to fire. As the car enters the frame, untwist your body to follow the car. Take the photo just as your body fully unwinds near the center. Your body should be moving in a smooth motion by now. Continue to follow through by twisting your upper body to the left side. If you practice this technique, you should be able to get a higher rate of success with your panning shots.
If you are on a tripod, you can also use the panoramic function if it has one. Just be sure to not lock down the tripod head so you can smoothly pan. And just like with panning handheld, take the shot midway through your pan, not at the beginning or the end of it.
Using slow shutter speed opens up a world of creativity with your images. Rather than trying to freeze everything in your images, try experimenting with various slow shutter speed techniques. You can add energy through movement in your photos, create an abstract world of ghostly motion blur, or create something tranquil with smooth, glassy water in the ocean.