Rear Curtain Flash Sync and Slow Shutter Speed To Catch Ambient Light Ambiance

AZ State Fair, 1/10s, F8, 22mm Nikon D90
Very Slow Shutter Speed Used with Rear Curtain Flash Sync. Note the pleasant overall rendering. Subject frozen and sharp. Background ambiance retained tastefully. AZ State Fair, 1/10s, F8, 22mm, Nikon D90, Nikon SB600 Flash set to TTL. View FULL size, CLICK image.

More light may be captured in cameras as a function of primarily four things:   larger apertures, more sensitive recording medias, slower shutter speeds and more available lights.

It was surprisingly elucidating to observe Phoenix, Arizona area wedding photographer Kenneth Robert’s methods for capturing and maintaining ambiance and moods inherent with existing light night and indoor settings.

Kenneth’s techniques utilized a rear curtain flash sync mode in combination with ultra slow shutter speeds.

In night and indoor photography, one of the ways we have more light available to record in our media is through use of various flash/strobe units.

Outdoors in daylight, ambient light is very high and flash may be used as a fill.  In night and indoor shooting, which are common in weddings and other photographic situations,  use of flash will expose our subjects and often leave backgrounds at any signficant distance behind our focus points dark to black.

This dark to black background effect also obviates much of the existing ambient atmosphere.

In some situations, we prefer this background darkening,  for example as a way to isolate our subjects.

AZ State Fair, 1/60s, F8, 18mm, Nikon D90
Using Flash and normal shutter speeds, background fades abruptly into darkness uninterestingly. AZ State Fair, 1/60s, F8, 18mm, Nikon D90, Nikon SB600 Flash.

What if we wish to keep the atmosphere of street lighting, colored disco lights or other ambiance intact while we still properly expose and freeze our main subjects using flash?

Well, rear curtain sync mode is one of the tricks here.

Kenneth sets his two Nikon D300 cameras to rear curtain sync in high-speed (FP) mode.

This type of flash sync mode is the kind which leaves pictures of tail lights of cars  behind a car at night.  A kind of cool rocket ship like effect.

The front curtain sync modes, usually the camera default flash setting, shows car tail light streaks in the same area as the car, generally a much less pleasing effect.

The second part of Kenneth’s technique involves the use very slow shutter speeds.

Maybe you recall the typical rule of thumb for 35mm full frame cameras is to steadily hold a shot at the inverse of the focal length we are shooting.

AZ State Fair No Flash 1/60s, F8, 18mm, Nikon D90, shot is too dark.
Using No Flash and similar exposure settings, we are clearly too dark with only ambient light. 1/60s, F8, 18mm, Nikon D90.

For example, the rule is, for a 100mm focal length, we hold the camera really really steady, hold our breath, and gently push the shutter release shooting at 1/100 second shutter speed…

With crop sensor cameras, which many of us use, we have to hold at even a bit faster shutter speeds due to increased telephoto effects.

Kenneth does not use, nor does this consider vibration reduction.

Armed with the example of a 100mm lens, swinging the camera wildly to and for, with hands held high, Kenneth may be shooting at 1/10 of a second, or even a tad slower.

What ever he feels is needed to bring in the ambient light.

Kenneth goes click, click, click, dragging his shutter at slower and slower speeds, until he gets the amount of ambient atmosphere effect he feels is satisfyingly appropriate.  He makes this adjustment visually using the viewer on the back of his full frame Nikon D300.

The rear curtain sync creates the pleasant effect of freezing main subjects at the end of their motions, much like with car tail lights.

With shutter speeds adjusted to whatever is necessary to bring in the ambient moods, Kenneth thus captures the atmosphere of the existing lighting, without the dark tunnel effect of high shutter speed flash effect many of us are used to.

Objects in the distance, being so far away, smaller and unlit by flash, are not so distracting as you might expect.  In any event, they are not the subject.

The object in this technique is to light and freeze the subject using flash, and to keep the atmosphere using slow shutter speeds.

Another really interesting technique was having a camera mounted flash unit (which may be used in command mode only or as a flash source) Kenneth could hold the camera out above his head,  above crowds, and aiming using the red laser light from the flash unit was able to frame his subjects, without need for having the camera view finder to his eyes.

This aiming method allows Kenneth to zip through crowds, point the laser, from any angle he can work his camera and arms into, and shoot, shoot, shoot…

Pretty cool stuff.

Give it a try and please comment to tell us how you make out?



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