Using flash effectively and learning about lighting is often the “final frontier” in a photographer’s journey to mastering photography. This is part two in a four part series on using your detachable SLR flash creatively. Part one covered flash to ambient ratios.
Now you should have a better idea how any photo taken with your flash is a combination of the exposure from the flash’s burst of light and the ambient constant light.
This article introduces flash blur or “shutter drag” which is a technique to make on-camera flash photos interesting. An added advantage is that it cleans up what may at first appear to be a cluttered environment.
Because the flash attached to your hotshoe is fixed in the same axis relative to your lens however you hold your camera, it’s a challenge to take photos with your flash in the hotshoe that look any different from those you might take with a compact camera. That’s probably one of the reasons you don’t use your flash much.
The shutter drag technique uses the ambient light to our advantage. This doesn’t work if you’re outdoors on a bright day; you need to be shooting somewhere, or at a time, when you’d be thinking it was about time to get your flash out.
It’s easiest to set your camera on the M mode, otherwise it will probably set your shutterspeed too slow, if it’s dark, or too fast if it thinks it should be at the maximum synch speed. It depends from camera to camera and mode to mode, but we want to be in control.
We’ll start at ISO400 and f5.6 or f.8 as they’re both good middle ground apertures; not so wide open (eg. f2.8) that your focus might not be accurate due to shallow depth of field, nor so stopped down (eg. F16) where your flash will have to be at, or near, full power.
Settings of 1/20th at f5.6 IS400 produced this appealing movement blur as a basis for our exposure.
With your flash off, set your shutter speed around 1/20 of a second and, as you pan your camera from left to right, press the shutter mid-swing. Your results should be slightly underexposed and blurred. Too dark ? Drop your shutter speed and try again. Too bright ? Raise your shutter speed. Your settings will depend on where you are. My first example photo is at 1/20 of a second in a tradeshow hall at New York’s Photoplus Expo 2010. Remember, this exposure should be on the underexposed side; a little dark.
Now turn your flash on and set it to TTL (or E-TTL or whatever your system calls it) and, with your camera settings unchanged, have a friend walk past you as you shoot them.
You should get something like this second example:
The shutter drag technique freezes the foreground, in this case a model walking past, while blurring the background. It’s a great technique for cleaning up messy backgrounds in crowded areas. Note the flash caught some of another passerby but a couple of minutes post-processing with Curves or Levels would subtly reduce that distraction even further.
As you can see, with this photo you get both the blurred background and a sharp subject. Why is the subject sharp and not blurred ? Remember your first test shot, before you used a flash, had to be underexposed ? That’s so that when we introduce the flash hitting our subject, with the TTL system correctly lighting her face, the short duration of the flash (hey, that’s why it’s called a “flash”!) freezes your subject. The background is too far away (mostly) to be hit by the flash. Voilá, an interesting shot with a hotshoe flash; a great exposure of your subject and a de-cluttered background.
Shutter drag works great if you have to shoot something in a hurry in a press-scrum or busy environment as the movement blur in the background often makes it a lot less distracting that it would otherwise be. This also works really well in nightclubs or really dark places with interesting background lights. Practice makes perfect… too long a shutter speed and it gets messy.
Using a slow shutter speed allowed the nearly totally dark alley to show on the final exposure, without distracting from the foreground element, the model.
You don’t even need to make the background blur. Just using this technique without any camera movement can bring out a pitch black background and make it a feature of the shot. My third photo was taken with a shutter speed of 2 seconds.
Although I didn’t want much camera shake, hand holding for 2 seconds is always going to result in some blur. I could have used a tripod but I was shooting fast so didn’t have time. I knew the thing that counted in the frame, the model, was going to be sharp as she was being flashed. She was lit with an orbis™ held out at arm’s length, a technique we’ll begin covering in the next part of this series when I’ll introduce off-camera flash.
I’m using the same technique here in a pitch black underground bar. To liven up the photo I used an 8 second shutter speed; I shot the girls and then waved the camera at the lights. The newspaper loved the unusual style and ran it. With practice you can get the light trails not to intersect your subject if you prefer it that way.
Links, resources and cool lighting sites:
- Strobist – lighting 101
- Dave Black Photography
- Orbis flash
- Enlightphoto on YouTube
- http://www.dg28.com/blog/technique/index.htm
James Madelin is inventor of the orbis™, a pro photographer and a lighting workshop tutor.
All text and images © James Madelin 2011
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