Feb
1

Shoot a stroboscopic flash sequence

by
Peter Fenech

Get creative with your speedlights or stobes

Flash is not immediately associated with sports and action photography, yet it plays an important role in the professional photographer’s workflow. Flash has a very short duration (hence the name ‘speedlight’) and can therefore create the effect of super-short exposure, freezing even the fastest of movement, without requiring high ISO settings, far above the native values. However, flash photography has much greater potential for creative imagery than simply freezing action. A popular technique in fast-paced action sequences is to capture the subject in multiple positions, using stroboscopic flash. This fires a series of high-frequency flash bursts, lighting an object in several places within the frame. This can help demonstrate the sequence of movements in far more detail than can be achieved in a single, conventional flash image. Here are the key steps to follow:


 

Step 1: Calculate movement duration

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 

 

 

 

Place the athlete or model on your set and have them practice their movement sequence. Measure the duration of the action using a stop watch and make a note of this value. Have them try multiple times to work out an average duration, to ensure you have an accurate idea of how your final frame may look.

Step 2: Work out your exposure

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Use a light meter to set the power of your speedlight or strobes, based on the duration of the movement and the resulting shutter speed you calculated in the previous step. Each strobe burst will create a perfectly exposed frame based on that. You may have to take numerous test shots of a stationary subject to perfect the light power setting.

Step 3: Keep your shot steady

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Put the camera on a sturdy tripod and connect a shutter release to avoid any kind of movement and improve sharpness. This is a vital accessory, as long shutter speeds are native to this type of photography. The best shots are those where the subject contains plenty of detail and sharpness, to contrast with the background and motion blur (if you choose to expose your images to create blur).

Step 4: Arrange your subject

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 

 

 

 

Switch the camera to manual mode. Set the exposure duration based on the length of the movement you want to capture and the f/no. based on the light meter reading.

Step 5: Create your composition 

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 

 

 

 

Decide on the number of stages you want to appear in your shot and set the appropriate number of flashes (measured in Hertz) on your flash unit. By setting a higher flash frequency, more ‘copies’ of your subject will be created, although these will be closer together in your composition. Be careful not to overlap each stage too much – if this happens, lower the frequency to produce greater stage separation.

Step 6: Shoot, review and repeat

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 

 

 

 

Start shooting and practice your synchronisation with the athlete. While this takes patience, it is essential if you are to capture the right combinations of stage numbers and overall composition. Try shooting a little wide to leave room for timing errors and crop in again later, in software.


Final image

Shoot a stroboscopic flash sequence

 

 

 

 

 

 

 

 



 

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