High speed sync flash for portraits

You know those pictures… perfectly lit pictures of people, looking natural, hanging out… a family having a picnic or enjoying a meal around the kitchen table, kids fishing by the pond, mum or dad soaking up the sun in a hammock? The kinds of pictures that look like easy snapshots?

Well, they’re miles away from snaps, but they’re actually not difficult to make once you’ve mastered the technique behind them – high speed sync. Most readily associated with outdoor sports and action images, turns out it’s ideal for lifestyle portraits, too.

Using the high speed sync mode with your Nikon DSLR (D7000 series and above) and compatibile Speedlights (SB-700, SB-5000 and some other speedlights such as the SB-900 range) will enable you to synchronise the flash to shutter speeds all the way up to your camera’s highest shutter speed. It works with all exposure modes, but is best used with the camera in manual mode, and you can use it with single or multiple Speedlights.

1. In your camera’s Custom Setting menu (the pencil symbol), scroll to Bracketing/Flash for the flash sync speed choices (the setting is usually E1 on most cameras).

2. Set the highest sync speed you see with Auto FP next to it. i.e. 1/320th or 1/250th Auto FP

3. Check on the LCD on the back of your Speedlight for the letters FP – your confirmation that camera and flash are now in high speed sync mode.

For a flattering soft background that eliminates distractions so that all eyes are on the subject, a shallow depth of field is vital. That takes a wide aperture (small f-number) such as f/1.4, f/2.8 or f/4, and out in bright sunlight that requires a shutter speed fast enough to prevent overexposure. High speed sync is what makes that fast shutter speed attainable. It can also be used to add atmosphere by darkening the sky, or to darken the background in order to conceal location distractions or details.

High speed sync can come into play for indoor portraits, too. In a brightly lit room, or one in which you’re bouncing your Speedlight’s flash off a white ceiling, you’ll need to boost the shutter speed to prevent overexposure.

In high speed sync mode, rather than the flash firing one burst of light, it emits an incredibly rapid series of pulses to illuminate the scene as the camera’s focal plane shutter moves across the sensor. This strobing action takes an enormous amount of flash power, so the flash essentially divides up the amount of light into segments as the shutter travels. The faster the shutter speed, the less flash power is available. Often the reduction in power doesn’t noticeably affect the image, but if it does, you can compensate by either moving closer to the subject or using more than one Speedlight.

Get to know what your Speedlight can do by practising with it in your garden or out in the street or local park on a bright, sunny day; play around with a range of shutter speeds (e.g. 1/500sec, 1/2000sec, 1/4000sec) to find out how it balances natural light and fills in shadows.

One of the most typical shooting scenarios for using high speed sync is shooting outside in full sun. If you have the light behind you and your subjects looking into it, they’ll probably be squinting, so instead try shooting with the sun behind them and prevent their faces from underexposing by balancing the sunlight with your flash.

Practice with your Speedlight off the camera, too, either hand-held or on a stand at, say, 45deg to the subject, as this will generally give better results than direct (camera-mounted) flash. If you’ve got a second Speedlight, however, you could mount this on the camera’s hot-plate and use it as a fill light.. When using two or more Speedlights, you can control them from the camera-mounted flash using the Nikon wireless remote flash system.