How to use your flash: Slow Sync Flash Tutorial

August 16, 2010 · 4 comments

in portraiture,Tutorials

In general, when shooting in low light conditions you have two options:
1.    Use a flash, which results in a well exposed foreground against an almost black background, or
2.    Use a slow shutter speed (ideally with a tripod), using ambient light to illuminate the background scene.

Slow sync flash, is a combination of both these techniques – using a slow shutter speed, with a burst of light from the flash – and results in a sharp subject, frozen by the flash, and a lighter background illuminated by the ambient light.


Step 1: Camera Settings
Many cameras have a setting called “Night Portrait” which makes use of slow sync flash, however I recommend setting it manually to gain more control and different creative results.

Select Shutter Priority on your camera, and then select a slower shutter speed.  The actual shutter speed you use, will depend on the result you want.

If you merely want to illuminate the background, then select a shutter speed between 1/60th and 1/20th. However, if you want a more creative image with motion trails, then experiment with longer shutter speeds of 1/10th – 1/4th and longer.

Step 2: Flash setttings
Front curtain sync
With most cameras, the flash fires as the shutter opens, freezing the subject in the starting position, and creating motion trails until the shutter closes.
Rear curtain sync
Specialised flash units allow you to set the flash to fire as the shutter closes, resulting in motion trails during the exposure, and a sharp subject frozen by the flash in the end position.

Step 3: Tripod or Handheld?
If you want to eliminate blur and motion trails, then without a doubt you should use a tripod. On the other hand, in some circumstances, hand holding your camera can create exciting effects. The flash freezes the subject, and in low light conditions, the subject or camera movements creates lights trails and motion blur.

Step 4:  Lighting

I like to use a diffuser, such as the Gary Fong Lightsphere and Bounce Flash techniques, as this produces a softer light source than direct flash.

Step 5: Creative Effects – Panning and zooming
Panning is when you move your camera horizontally while the camera is recording, stopping at the subject matter, and zooming is when you zoom your lens in / out while the camera is recording. The latter creates a tunnel like suction and combined with slow sync flash, creates exciting light and motion trails

Experiment with different shutter speeds, front and rear curtain sync, and with panning and zooming techniques, and you never have to use direct flash and get “deer in headlights” again! Horray!

{ 4 comments… read them below or add one }

Erika van Zyl August 17, 2010 at 5:56 am

This is very interesting – and you make it sound so easy!

rikki hibbert August 17, 2010 at 8:51 am

It IS easy, and with digital photography, experimenting gives instant results! ;-)

L'Zeri Swart August 19, 2010 at 8:30 am

I’m printing this out!!! Elfranco & I will be trying it out over the weekend.

rikki hibbert August 19, 2010 at 8:32 am

Have fun! You will be amazed with the results! ;-)

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