Stroboscopic or Repeating Flash
10 Feb 2013
Stroboscopic Photography or Repeating Flash Photography
Capturing motion in a single frame.
Stroboscopic photography is using multiple light sources all firing in sync repeatedly to capture the motion of an object or person during the length of the exposure. While my definition and explanation may sound boring the images produced from this kind of photography can be very beautiful and quite unique.
To do stroboscopic photography you will need at least two strobes, I used four, a support system to suspend them above your subject. A mechanism to trigger all the strobes simultaneously, and your camera should be mounted on a good steady tripod to minimize camera shake during the long exposures you will be using while making these images.
While the camera shutter is open (exposure time) the strobes are going to flash X number of times at X hertz. To obtain your exposure time you divide the number of flashes by the hertz and this should give you a rough exposure time.
For example if the strobes are going to flash 10 times at 5 hertz, you divide the number of flashes by the hertz which in this instance gives you an exposure time of 2 seconds.
If you had the strobes flash 10 times at 10 hertz the exposure time would be 1 second.
The only two remaining variables are the ISO and F stop. Personally I use ISO 200 or lower and F stop usually ranges from F4 to F7.
Here is a list of equipment I used to produce these stroboscopic images.
1 x Nikon D3s
1 x Gitzo G1325 Tripod
1 x ReallyRightStuff BH-55 Full Sized Ball Head
1 x ReallyRight Stuff BD3-L: L Plate for all D3 Series Cameras
4 x Nikon SB-900 AF Speedlight (strobes)
4 x Nikon SD-9 High Performance Battery Packs
Lots and lots of AAA size batteries
4 x Manfrotto 175F1 Spring Grip Clamp with Attached Flash Shoe, I replaced the shoe that comes on this clamp with a Frio Universal Locking Cold Shoe.
1 x Nikon SU-800 Wireless Speedlight Commander
1 x Giottos Free Standing Background Support System
1 x Giottos BR-3, 3-Section Background Crossbar Set with Connectors, Extends to 9.9 feet
1 x Beautiful, graceful model who has the patience of a saint and loves being the subject for a potentially cool image.
Once you have all this equipment setup and the model is ready, you must explain what is going to happen as this type of photography is quite different from the way strobes are typically used. I have found that it is best to trigger all the strobes while the model is standing next to me so she can see what is going to happen while she is moving across the space beneath the two, three or in my case four strobes.
When the demonstration is over it is time to start shooting. My experience has taught that it is best to do a count down before triggering the camera and the strobes. 3 - 2 -1 GO. By the time I say GO the model should be in motion. Then stand back and watch what happens. Even without looking at the images on the back of the camera what you will see is very, very cool looking.
Hope this is helpful to someone