Tips & Techniques » Shutter Drag: Add Color and Movement to Your Images
|A little or a lot - Your shutter speed and the motion of your subject or camera controls how much sharp and how much blur there is in a shot. Here I've managed (with a little luck and good timing) to capture a shot with just a small amount of motion that helps convey the giddy mood of the subject.|
The technique called Shutter Drag is a versatile trick used to combine ambient light with the illumination from your flash. Its effects can run the gamut from subtle to dramatic to downright impressionistic.
One of the defining characteristics of a photo that's been shutter dragged is its blurry sharpness. Huh? That's right – areas of the photo that are exposed by the flash illumination are rendered sharply while other areas show signs of movement and blur.
Shutter drag is achieved by intentionally using a slow shutter speed to allow the ambient light of a scene to be recorded while a flash fires and adds its own effects to the exposure. It is most commonly used when the ambient light is low – dawn, dusk, sunset, indoor lighting, etc. - but with the proper settings and equipment it can be done in the full sun too.
How to shutter drag:
Some of the basics of this are covered in my previous article Introduction to Flash, so be sure to read that if anything starts to sound Greek to you.
|Shutter drag is a great technique to use when photographing parties or events. Allowing the background ambient light to bleed into your photo gives the shot a sense of place and atmosphere.|
Syncing Slowly with Automatic Settings
Novices and new experimenters may want to start out letting the camera do some of the thinking. Remember that the camera manufacturers want to do everything they can to help you take sharp pictures – they add red warnings when the light is low, provide image stabilization and tend to program their cameras to favor faster shutter speeds to avoid blur. Unfortunately, that thinking can lead to some dull and lifeless flash pictures in low light. Now it's time to wrestle some of that thinking away from the camera to get more colorful and dynamic photos. Luckily, there's a button for that...
Whether you are using a pop-up flash on your DSLR or an accessory flash, your camera most likely has a flash setting or a specific mode called Slow Sync. Using Slow Sync lets your camera know that you want to allow the shutter to stay open longer to allow more ambient light to reach the sensor.
Classic situations in which to use shutter drag are taking photos indoors at a party or portraits against a sunset background. It's easiest to start by setting your camera into Aperture Priority mode with Slow Sync flash. At this point, your camera is going to start metering for the overall ambient light in the viewfinder – as you spin your aperture dial, you'll see your camera's shutter speed selection changing to match. Take a test fire and notice what you get. Now you can make some adjustments.
The three main adjustments you'll make now are:
I recommend you make time for an experimental outing to play with these factors, even if it's just in your home. There can be a lot going on in a photo with these settings so take the time to observe the changes that adjusting one variable at a time does to your outcomes. Have fun, but pay attention! Even consider taking notes for each shot so that you can analyze them later.
|Pinpoint your subject and make everything else move. Careful flash placement and direction (isolated toward the subject and away from the ground) while panning with a slow shutter speed helped me render the little racer while turning his sidewalk racecourse into a speedy blur.|
Taking Total Control in Manual Mode
There's nothing wrong with using the brain built into your camera as long as you use yours too. For some photographers and for some situations using only your brain and not letting the camera make any decisions can be the answer. The concepts are all the same as above, but you're in full control.
Let’s switch to Manual Mode. First dial-in your aperture, remembering that the aperture is what determines how much light your flash needs to pump out to accurately expose your subject. If you are using your flash in TTL mode (OK, the camera is still doing some thinking here) you should be able to pop a well-exposed shot of your subject here. You can also dial in a little +/- flash compensation to taste. If you've gone to full manual flash then you'll either have to adjust your flash's output to match your aperture or vice versa.
Once you've got a basic flash exposure set, simply start playing with your shutter speed dial to change the background exposure. I generally like to look at my meter and start with a shutter speed that will give me 1 to 2 stops underexposure on the background – but there are no rules. Remember that the flash fires during a fraction of the time that the shutter is open, so changing the shutter speed has no effect on the flash part of the exposure. (Some cameras have a maximum shutter speed, for instance 1/250th, above which the flash will not properly sync. This can be seen in an image which has a distinct line which looks darker than the rest of the image - as if a curtain had been drawn.)
Now it's back to experimenting again, finding the right combination of slow shutter speed and flash exposure to suit what you think the scene needs. There is no right or wrong answers here – you're in control and have full freedom to cook the photo to your liking.
|Here I was captivated by the vibrant green of the plant as contrasted against the fading deep blue light of the evening. I experimented with several different shutter speeds while I purposefully shook the camera during exposure. Shaking the camera allows the silhouette of the leaves against the sky during the non-flash part of the exposure to become ghost shadows around the flashed exposure, giving the leaves the look of having been shot against a painted backdrop.|
Playing with Blur
When shutter dragging you may want to have the background reasonably sharp – you may for instance want to show what's happening at the party behind the flash-exposed subjects in your foreground. Or you may want to liven things up to tell a story with movement. Slowing the shutter allows people in the background to become blurs as they move out of range of the flash's motion-freezing burst.
You'll find that at certain shutter speeds your inability to hold the camera perfectly still for the duration of the shutter's open time with allow the background to blur onto the edges of your flash exposed subject. This can create some interesting and stylized effects. Alternatively, to add more of this, you can intentionally shake your camera during exposure. I like to start by beginning to jiggle the camera before I hit the shutter button so the camera is already in motion when the shutter opens. Play with this – you can get some beautiful backgrounds that are just smeared with colors. This technique can add a compelling sense of movement and action in the photo. Other options to induce movement include panning with a subject as you release the shutter, or even zooming your lens in or out when you release the shutter.
Rear Curtain or 2nd Curtain Sync
Another setting to experiment with is the Rear Curtain AKA 2nd Curtain sync. By default the flash is usually synchronized to fire at the exact moment that the shutter is first fully open. Setting a 2nd or rear curtain sync causes the flash to fire at the last possible moment before the shutter begins to close.
What's the difference? When using a slow shutter speed with flash, things that are moving will blur during the long shutter speed but will be frozen when the flash pops. Let's say a car is traveling through your frame. In a default (front curtain) sync , the car would be frozen immediately by the flash, but would then begin to blur as the shutter stayed open. In a rear curtain sync, the car would blur and THEN be frozen - this provides a much more logical picture in our minds as it appears that the car is moving forward. In a front curtain sync, the blur appears ahead of the frozen car and makes it appear to be moving in reverse.
For moving subjects, select a rear curtain sync. Unless, of course, you want them to look like they're going backward...
I Dare You to Take a Blurry Photo
While many people are combing the internet worrying about how sharp their lens really is or whether their camera is as good as the latest-greatest for sharpness and resolution, go out and practice some shutter dragging. You owe it to yourself to see that having some unsharpness and camera shake in your photos can be a great thing. And while you're at it, you'll be taking a picture of a reality as only a still camera with an attentive operator at the controls can see it. Have fun!