The Complete Guide to using Motion Blur in your Photography
Sharpness is one of the things that make a picture stand out. We get better glass, use a tripod, increase shutter speed and stop down to a narrower aperture to get a sharp picture. This is why most hate blur in their photographs. But we can use the blur as an artistic reagent to create something fascinating. This can add a sense of depth and movement to an image.
out of focus (cc) by marfis75
There are two major ways you can capture motion blur. You can either blur the background by panning the camera or blur the subject by staying put. Fortunately, there is only one main step in getting motion blur – slower shutter speeds.
Slow Down Your Shutter Speed
The value of your shutter speed is dependent on the speed of your subject. Certain subjects need a couple of seconds while others might just need 1/60 of a second. Capturing a person running and a car drifting with the same shutter speed will yield totally different and somewhat unsatisfactory results. The faster an object is, the faster you can set your shutter speed and still see motion blur. Keep in mind that there is no exact formula in getting the right shutter speed. Much like other style of photography, just keep on experimenting to get the best results for you.
Be wary though, there’s a catch with slowing down your shutter speed. Light will have more time to enter your camera’s sensor and this can overexpose your shot if not taken into consideration. Fortunately, there are various ways to compensate for this.
Firstly, you can use a smaller aperture opening. If you’re familiar with how exposure works this should come naturally to you. As you slow down shutter speed by a full stop (1/250 to 1/125) you double the time the shutter is open. The same goes with aperture. As you increase the opening of the lens to a full stop (f/5.6 to f/4.0) you let twice the amount of light to enter. Basically, if you decrease your shutter speed by a stop, you can widen your aperture by a stop and you still get the same exposure value. If this gets a bit complicated, you can always use your camera’s shutter speed priority mode and let your camera handle the exposure compensation. This is just a last resort though, it’s ideal to know the technicalities of exposure since it opens up other venues in photography.
Secondly, you can change the value of your ISO. Higher ISO means that your sensor is more sensitive to light and lower ISO value means it is less sensitive to light. Since we are using slower shutter speeds when capturing motion blur, it is advisable to use the lowest possible ISO value to get the proper exposure.
As a last resort, you can always attach a neutral density filter to your lens. It’s almost impossible to shoot in a brightly lit situation using seconds for you shutter speed without resorting into neutral density filters. You can try using your lens’ narrowest aperture value but this will introduce diffraction and might ruin your shot.
If you want to put blur to your subject, make sure that your camera is stable and not moving at all. Using slow shutter speeds will capture any slight movement from the camera and will ruin your shot. A good tripod would be ideal in these kinds of situations. Water is a good subject for this kind of blur. From seascapes to your household faucet, adding motion blur can add a sense of calmness and makes the water look quite ethereal.
Rocks in a River by mhillier
On the contrary, if you want the background to have motion blur, you need to follow your subject via panning the camera to the direction where to subject is moving. This might need some practice at first since photographers are used to keeping their camera stable at all times. This technique can be used in racing events where shooting at a fast shutter speed makes the cars look so static. Adding background blur adds a sense of movement to the image.
panning by tambako
Slow Sync Flash
Another way to convey motion is by using your flash. Most cameras have a setting to change how the flash works. Instead of firing at the start of the exposure, it pops at the end of it. Find the Rear Curtain Sync setting of your camera and switch to that. This technique can be used in clubs when you want to convey movement while still having well exposed and tack sharp images.
Heat Lightning by patdavid
Like other areas of photography, getting a hang of capturing motion blur will require practice and experimentation. Getting the right shutter speed and exposure will definitely help in achieving great images. The only way to get good at it is to practice and take plenty of photographs. If all else fails, you can try adding blur via post processing to your pictures here.