Brooks Pro Tip: How to Create Stop-Action Images Using Your Flash
March 13, 2013
•Scott Miles
•General, Brooks Pro Tips, Photography
• 0 Comments
As photographers, we often look for ways of creating images that cannot be seen by the unaided eye. Stop-action photography is one technique that allows the photographer to do this.
We can approach all sorts of different applications, stop-action photography among them, by understanding the theory and basic functions of equipment. For example, many modern flash units (speedlights) can be effective for stop-action photography.
The Basics: How to Set Up Your Flash
In order to freeze the action of fast events, we need to have a very short duration of light from the flash. If you push a lot of power through a flash tube, it takes more time for the energy to create the higher level of illumination. If we send less energy, the flash tube will illuminate for a shorter duration.
So, a basic starting point for stop-action photography is to use the lower power settings on your flash unit – for example,1/16 or 1/32 power should work for to photograph a water drop. (You can always increase the power a little in order to test to see if you still have a short enough flash. Just look for motion blur in the subject and decide what power setting works for that subject.)
If we wish to freeze a water drop impact, as shown below, we need a flash duration of about 1/10,000 second (more details on capturing this shot are shared later in this post). There are many other stop-action subjects that provide fascinating photos. Experiment to find what flash duration is needed to get the desired stop-action effect for that subject.
Image © Blake Estes
The Challenges: Lighting, Depth of Field & Timing
It’s easy to say, “Just use low power settings on your flash and you will get great stop-action photos.” However, one challenge is the very low depth of field that results from low-powered flash (low light = large apertures = little depth of field). Another challenge is creating lighting that renders reflective surfaces (like a water drip) effectively. Also, timing the photo is a big problem, unless you have a triggering device.
We use short-duration strobes (Profoto 7A and Paul C. Buff Einstein) and sophisticated strobe triggering devices (Cognisys StopShot) for the work our students produce in the Stop-Action Photography class at Brooks Institute. If you are not able to spend about $500 for a strobe plus about $400 for a drip kit triggering device, then it is possible to simply use a detachable flash with manual control and a DSLR camera. It takes a lot of patience to do this, though, since precise, repeatable timing of the capture is not possible without an electronic triggering device such as the Cognisys StopShot.
Experimenting with Stop-Action Photography
To start experimenting with these techniques, set up in a space where you can eliminate all light. Since you’ll be using short-duration flash, you need to eliminate other light that could create a blurred, longer-exposure image. Set up a shallow tray of water with a dark bottom and plastic tubing to drip the water. Place the camera on a tripod (absolutely required!) and frame up your photo.
Keep in mind that the surface of the water is just like a mirror. Set up the camera so that it is viewing the water surface at an angle. Set up a white or colored piece of smooth-surface board so that it reflects into the water surface. Point your flash at the white or colored card so that it will be illuminated by the flash and reflect into the water surface. Whatever gradation, color or brightness that you create on the card will appear reflected in the water surface, with the drip impact clearly visible.
Rig the drip tubing so that the drip impact is in the same place each time. Focus carefully on that spot. With all other lights off, set your camera on the fastest flash sync shutter speed (generally 1/250 sec) and shoot away as water drips from the tube. Be thankful that we have digital capture – it takes lots of frames to catch a drip!
The water drop photo shown above was created for the Stop-Action Photography class at Brooks Institute by Blake Estes, who used techniques similar to those described in this posting (he did use a precision triggering device to time the strobe firing at the precise moment and professional studio strobes).
Scott Miles is an instructor in the Professional Photography program at Brooks Institute.