Monday, March 29, 2010

The Balancing Act Of Flash On Location

By Mark Edward Harris Published in Photography Lighting
The Balancing Act  Of Flash On Location
Tamrac MicroSync

Of course, we often don’t want to neutralize all colors; the lower numbers on the Kelvin scale can add warmth to a scene. It’s important to understand that just as there’s no one daylight Kelvin temperature, there’s no one tungsten temperature. For example, a candle flame is approximately 1850 K, and incandescent light bulbs fall typically into the 2700-3300 K range. Daylight and electronic flash units range from 5500 to 6000 K, with an overcast day going toward 6500 K.

Quantum QFlash 5d

The Key To Life Is Balance

It’s important to consider the fact that daylight isn’t just one color temperature; it changes throughout the day. Other factors such as weather and location—snow, sand, altitude—come into play. For example, your eye sees blue when it sees snow on a sunny day, but your brain thinks white, discounting the sky’s reflection. The photograph will reflect the reality, not what’s in our mind’s eye. Shooting with a straight flash with its cool color temperature might be perfect for that, but completely off for a sunset. This is when adding gels in front of the flash is the solution.

I cut CTO gels into strips to tape over my flash starting with 1?8 CTO. This warms up my flash to approximately 5400 K. If I need to go warmer, a 1?4 CTO will warm things up to 4800 K, a 1?2 CTO will convert the daylight to 3800 K, and a full will convert it all the way down to 2900 K. If I need to go the other direction (which is much rarer), CTB (color temperature blue) is used.

PocketWizard Multimax

For my outdoor work, I use the flash for filling in harsh shadows on people’s faces or to add drama to an environmental portrait by making the flash a keylight and underexposing the background. In both cases, I’ll establish my ƒ-stop and then adjust the shutter speed in manual mode to decide how dark to make the background. I do this quickly, since the people I’m shooting are real; I can’t ask them to wait around while I experiment. If I’m stopped all the way down, I get to my sync speed of 1?250 sec., and if the background is still too bright, I’ll reduce my default outdoor ISO from 200 to L1 (effective 100 ISO) on my D3 and bump up my flash output one stop. For more extreme results, the Auto FP High-Speed Sync can be an option.
There’s a time and a place for overpowering the ambient light, which Annie Leibovitz has done for years—remember the great shot she did of basketball center Wilt Chamberlain and jockey Willie Shoemaker on the beach for an American Express ad? For my shot of a grandfather showing off his granddaughter on the Iranian island of Kish in the Persian Gulf, I used this basic concept. I took an ambient exposure of the sunset and silhouetted the rusting remains of a Greek ship. With that exposure established at 1?250 sec. at ƒ/5.6 at the L1 ISO, I quickly adjusted my output on my Nikon Speedlight SB-800, then raised it high and to the left. The 1?4 CTO taped over the flash’s head gave a good balance to the resulting image. I did similar approaches for my photographs of a young fisherman on Inle Lake in Myanmar and a traffic officer in Pyongyang, North Korea. Because they were both done with the sun higher in the sky, I used a 1?8 CTO over the flash.

LumiQuest FXtra

Working Without A Wire

My Speedlight SB-800 and the newest Nikon flash, the Speedlight SB-900, can be fired off-camera by the use of cords, such as the SC-29, which has a built-in AF illuminator, or the SU-800 Wireless Commander, which is compatible with the Nikon Creative Lighting System (CLS) for cordless off-camera flash operation. Photographers such as Joe McNally are doing incredible multiflash setups with CLS. With this wireless lighting system, the out-put of up to three groups of remote Speedlights—each group comprised of a practically unlimited number of Speedlights—can be controlled from the camera position.

Soften The Blow

The Speedlight SB-800 comes with a diffusion dome, which I’ll occasionally use to soften the light. Sometimes, I’ll tilt the flashes head-up and let the light bounce off my hand for a soft light. Of course, there are many interesting light-softening devices in the marketplace (I use Gary Fong’s Lightsphere flash accessories, but there are other options, as well).

Digital cameras, because of their immediate feedback, have been an incredible aid to photographers working creatively with flash. Flash-fill has given me the ability to extend my working hours so I can shoot even under the midday sun, which according to playwright and composer Noel Coward, was supposed to be the domain for only mad dogs and Englishmen.
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