All surfaces reflect light.
All surfaces reflect light that is the same color as the reflective surface. Photographers use reflectors to control contrast and color temperature. Reflectors may be homemade and commercial reflectors are available in a wide range of sizes. Large reflectors are broad and diffused light sources that soften or eliminate shadows, and small reflectors are narrowly concentrated light sources that create deeper and darker shadows.
Nature
A field of grass reflects green light.
Nature provides various planes, such as grass and snow, that reflect light. A field of grass reflects green light, and photographers may wish to adjust color temperature settings on their camera to compensate for the green colorcast. Snow generally bounces light back up at the subject from below. Snow may produce undesirable affects if the photographer does not adjust the exposure to compensate for a subject that appears too dark or light when evaluated by the camera's light meter.
Flip-up or Pull-out
Some detachable on-camera flash head have small bounce cards.
Some detachable on-camera flash units have built-in reflectors. These are small white or colored cards attached to the flash unit that either pull up or flip out adjacent to the flash head. These small reflectors allow photographers to light subjects with light that is more diffused than direct flash lighting, but act as small light sources that create deeper and darker shadows than larger reflectors. The thin slot directly above the flash head in this picture houses a small pull-out bounce card.
Commercial Disks and Panels
Commercial reflectors may be rigid surfaces such as cardboard poster board, or soft surfaces such as fabric sheets or collapsible photographic discs, and are available in a wide variety of sizes. The most common are white, silver and gold. White surfaces reflect approximately 90 percent of the light that falls on them, and create slightly warmer light than the original light source. Gold reflectors reflect most of the light that falls on them, and create warmer light that is more orange than the light that falls on them. Silver reflectors reflect most of the light that falls on them, and create cooler light that is more more blue than the light that falls on them, but usually create darker shadows.
Black Reflectors
Black reflectors are used for subtractive lighting. They can be rigid such as cardboard or poster board, or soft such as collapsible photographic fabric discs, or homemade from black paper and fabric. They are commercially available in a wide variety of sizes. This reflector helps create shadows by absorbing light that would otherwise fall on the subject.
Ceilings and Walls
Cielings can create soft diffused light with flash photography.
When using a detachable on-camera flash unit with a head that swivels, a photographer may be able to use the illumination provided by a large light source. Aiming the flash head up towards a white ceiling will reduce shadows created by the flash's bulb, and this will give much softer light that bounces from the ceiling back on to the subject. Aiming the flash head at a wall that is in front of or next to the subject bounces diffused light back onto the subject.
Basic Flash or Strobe Reflector
Basic reflectors help concentrate the light from a light source.
The basic reflector fits around a flash tube head. It can be used to concentrate or spread the beam of light emitted by the flash. These reflectors are available in a variety of matte and high-gloss finishes, sizes and sidewall angles. Each variant allows photographers to adjust the spread, throw and harshness of the flash.
Bounce Umbrellas
Umbrellas reflect non-directional light.
Most commercial photographic umbrellas are black on the outside, and are available with a variety of reflective finishes on the inside. Lighting units are mounted to point into the umbrella. The light bounces around inside of the umbrella, and then out toward the subject as non-directional lighting. The light reflected from a photographic umbrella is typically smooth and soft.
Gray Card
Gray cards are used to calibrate the exposure of shots taken under particular conditions. Gray cards are cardboard or foam board reflectors that reflect 18 percent of the light that strikes its surface, while absorbing the rest. Since light meters in DSLR and SLR cameras are calibrated to view all images as if they are 18 percent gray, photographing a gray card to calibrate the exposure under particular lighting conditions ensures that the exposure is well calibrated (See References 1).
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