Intentional camera movement is taking a photograph with a longer shutter speed and purposefully moving the camera during exposure. Most photographers swear by using a tripod for this technique, but I'm here to show you that you can do it handheld just as easily.
Intentional camera movement is the process of moving the camera during an exposure in order to purposefully produce image blur for creative purposes. It's different than camera shake blur, which is the unintentional blurring of a photograph due to incorrect camera settings, low light, or due to the camera not being kept still enough.
ICM is done with a longer shutter speed in order to achieve these blurred results, and photographers commonly use tripods to steady the camera during exposure, often with a three-way tripod head that allows the locking along the horizontal or vertical plane for intentional blurring in only one specific direction.
Does that mean you can't do ICM if you don't have a tripod or a three-way head? Of course not. You just have to be a little more careful with your camera movement and the settings you dial in. So let's take a look at how you can shoot ICM photographs handheld.
Time It Right
The most important step to getting a good ICM shot is in the length of the exposure. The shutter speed should be long enough to get camera movement blur, but only just. As a general rule, start at 1/10th the length of your lens' focal length and then go slower from there. For example, if you're shooting on a 200mm lens, then use 1/20 sec shutter speed as your starting point.
Aperture and ISO sensitivity don't matter too much here, so it's easiest to just use shutter priority mode if you don't feel comfortable setting your exposure in manual mode. If your shutter speed isn't getting long enough because the scene's too bright, then drop down your ISO sensitivity or stop down. If it's still too bright, you might have to use a neutral density filter to darken the frame.
Focal length will determine the shutter speed required to acquire sufficient blur. A longer lens requires a shorter shutter speed. Wider lenses will need much longer shutter speeds because their field of view is so wide and a small camera movement will be more difficult to register as blur. I've taken all these ICM images on a 70-200mm lens shot at 150mm.
Start by widening your stance and putting a little bend in your knees (if you're standing). Lock your elbows in towards your body and steady the lens with the left hand underneath it. Then, move in the direction of the subject's shape to retain the detail of your subject. For my forest shot, I moved vertically, because that's the direction of the tree growth.
You have to balance the speed of the camera movement with the length of the shutter speed. I can't tell you exactly what that should be, as it depends on which focal length lens you're using, the available light, and how fast you're moving the camera. Also, it depends what you like the look of: if you prefer a more blurred shot, then you'll want to go longer with the shutter speed or move the camera faster (or both). In my photos, though, I used 1/8 sec at 150mm with an aperture of f/2.8 and ISO 100.
Issues You'll Encounter
The Shutter Speed Isn't Long Enough
For me, there's not enough blurring in the above photo to make it look good. Remember, the technique is called intentional camera movement, and this shot just looks like unintentional camera shake blur. Also, there's a little too much detail in the trees for my money. You'll also get the same issue if you're not moving the camera fast enough.
Not Moving in a Consistent Direction With the Subject
Look at the edges of the trees here, and you'll see jagged edges. It looks like aliasing in a video game, where edges are smooth and straight but stepped and odd-looking. But the reason for this is that it's actually because I wasn't moving consistently in the direction of the tree growth. There was a little side-to-side movement during the exposure, which caused this jagged outline. That's why most photographers use a three-way head on a tripod, as it avoids this kind of issue, but to be honest, it only took me a few seconds to get a handheld shot that was perfectly straight, so it's not really an issue.
Image Stabilization Will Help
Shooting on a lens with IS will help with getting things looking right, as it'll smooth out all the imperfections of movement as you wobble the camera back and forth. In fact, any kind of IS will work, so a camera with in-body image stabilization will also benefit this kind of photography.
Experiment With the Technique
Try going longer again with the shutter speed or moving the camera even faster. You might find in some situations that an even more extreme blur will produce gorgeous, silky results. In the above photo, I used exactly the same camera settings as before (f/2.8, 1/8 sec, and ISO 100), but this time, I moved the camera much faster during the exposure, and the trees have lost a lot of fine detail, becoming more line-like.
I really love handheld photos for intentional camera movement, because they allow me to travel light (without a tripod), and there's less setup time. What's great is that almost every photo is different. The composition changes as you take photos, because you're constantly tilting up and down (or panning left to right), firing shots off as you go, and the results look different if you switch up movement speeds or shutter speeds. It's an incredibly fun way to get some more conceptual photos.