The Wonders of Flash Page 7

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One neat flash technique is to combine it with a slow shutter speed outdoors, panning the camera to follow an action subject. The slow shutter speed blurs the ambient light exposure, while the brief flash duration freezes the nearby moving subject—a different effect than a straight available-light slow-shutter pan. Photo by Bryan Nylander

Many higher-end shoe-mount flash units have a repeating or "strobe" feature, in which flash can be set to fire several bursts in very rapid succession. This allows you to make strobe-effect photos. This technique works best in a large room with dark walls, or outdoors on a dark night, to keep the background from being overexposed by the repeated flash bursts. If you can move the flash unit off-camera, place it to one side of the subject (as done here) so it doesn't illuminate the background. Photo by Mike Stensvold

Because the flash burst is effective only for a relatively short distance, you can produce unusual flash effects by placing a colored filter over the flash tube to color a nearby subject, while the rest of the scene remains naturally colored. (Here, the highly reflective license plate picked up the flash, but the rest of the background appears normal.) Photo by Mike Stensvold

Painting with light is a fun technique. This lighthouse was lit with a single Nikon AF Speedlight shoe-mount flash unit. For the "straight" shot, on a dark night the camera was attached to a sturdy tripod, the shutter held open on B for 30 seconds with a locking cable release, and the flash was fired several times near the right side of the building, "painting" it with light. The flash was then moved to the other side of the building, the shutter opened for another 30 seconds, and the flash was fired several more times to paint that side. (Note: It helps to have an assistant when doing light-painting.) For the colorful shot, the same technique was used, but a blue filter was placed over the flash for the bursts on the right side of the building, and a red filter was placed over the flash for the bursts at the left side (where the flash beams overlapped, magenta appears). For the color-effect shot, a very-high-intensity flashlight was directed at the lighthouse lens for a third 30-second exposure on B. Photo by Jack and Sue Drahfal

If your camera doesn't have multiple-exposure capability, you can still make double-exposure "twin" shots using your flash unit and a darkened room. Just set the camera up on a sturdy tripod, position the subject on one side of the frame, darken the room, open the shutter on B and fire the flash, then have the subject move to the second position and fire the flash again. The room has to be really dark, and this works best with a dark background. Photo by Ron Leach
Off-Camera Flash
Direct on-camera flash is not the best lighting for portraits, because it casts an unattractive shadow on the backdrop behind the subject, provides little modeling of the face, is harsh and produces red-eye.

You can eliminate the shadow from the backdrop by moving your subject farther from the backdrop (the only solution with built-in flash units) or by raising the flash unit up high enough so that the shadow is cast down out of the picture area. Raising the flash unit has the added benefit of eliminating the flat, unexciting look of direct frontal lighting. Positioning the flash unit 45° to one side of the camera and 45° above it is a good starting point for the main light in flash portraiture.

Note: When you move the flash off-camera, remember to use the flash-to-subject distance, not the camera-to-subject distance read off the lens' focusing scale, for exposure calculations. Some of today's SLR cameras offer accessory off-camera TTL sync cords that let you move the flash off-camera yet still retain full TTL flash automation, and a few offer wireless off-camera TTL flash capability. These systems automatically handle the exposure for you.

Bounce Flash
You can soften the light by bouncing it from an umbrella reflector or other large white surface, such as a sheet of poster board or FomeCor. Umbrella lighting is attractive and forgiving—there are no harsh shadows to shout "bad lighting" at the viewer. If you have just one flash unit, bounce it and you'll be pleased with what you can do with that single unit.

If you don't have an umbrella reflector, you can bounce the flash off a nearby wall or ceiling. A white wall is a good choice, because it reflects side or side/front lighting, depending on whether you position your subject with the wall directly to one side or with the wall more in front. Ceiling bounce light generally comes from too high an angle to produce flattering people pictures, but is useful for providing overall illumination while eliminating the flat look of on-camera flash. Don't use a colored wall for bounce lighting—your subject will take on the wall's cast in the resulting color photograph.

Many shoe-mount flash units have heads that swivel and tilt for bounce lighting while retaining full TTL flash automation. If your flash unit/camera combination doesn't offer this capability, you can determine exposure for bounce flash (whether off a wall or an umbrella reflector) by using a flash meter, which reads the flash burst and tells you what aperture to use for the shot. If you use multiple-flash-unit lighting setups, the flash meter is about the only way to determine exposures (although some AF SLR cameras provide TTL flash control with multiple flash units, via special sync cords or wirelessly).

If you have to determine exposure for bounce flash manually, measure the distance from the flash unit to the reflecting surface and add this to the distance from the reflecting surface to the subject. Calculate the f-stop based on this combined distance, then open the lens one stop from the resulting exposure. And bracket exposures to compensate for variations in bounce surfaces.

Because bounce lighting increases the flash-to-subject distance, and some light is lost in the reflecting process, you need a fairly powerful flash unit to use bounce lighting.

Red-Eye
Red-eye occurs when the flash unit is too close to the lens. This causes the flash to reflect off the subject's retinas, right back into the lens. Large red spots in the eyes are the result in color photos (white spots in black-and-white).Red-eye has ruined many a portrait (be it of people or animals—with animals you sometimes get yellow-eye or green-eye).

The only way to eliminate red-eye is to move the flash unit away from the lens—above or to one side of the camera. Obviously, built-in flash units can't be moved off-camera, so most camera manufacturers incorporate a red-eye-reducing (not eliminating) feature, such as pre-exposure flash bursts that "stop-down" the subject's eyes to minimize the effect. While fairly effective, such pre-exposure bursts do affect the spontaneity of the image.

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