Aperture:
The aperture is the opening behind the camera lens through which light passes on its way to the image sensor. It is adjusted to open and close in f-stop increments, allowing more or less light in with a larger or smaller opening. Each aperture opening, or f-stop, lets in twice as much light as the smaller f-stop before it, and half as much light as the larger f-stop after it. For example, f5.6 will let in twice as much light as f8, and half as much light as f4.

Automatic Mode/Automatic Exposure:
The automatic mode is a setting on your camera that allows the camera to use its internal meter to automatically adjust the aperture and shutter speed for a shot based on the prescribed ISO speed of your film, and the available light. When using studio flash units, you can not leave your camera in automatic mode, as its internal meter will not be able to detect the light that will be emitted by your flash units, and will thus be set to an inaccurate shutter speed and aperture opening, causing your picture to be overexposed. Furthermore, when in automatic mode, many cameras have TTL metering which will send out an infrared signal to read the light, and that signal may inadvertently trip your unit’s built-in slave tripper.

Ambient Light/Available Light:
Ambient, or available light refers to the light that already is present in the location where you plan to shoot. This light could be sunlight or indoor overhead lighting. Typically, when using studio flash units, the ambient light will be overpowered by the direct flash. However, it is important to factor in any ambient light in your flash meter readings to insure a proper exposure. BCPS (Beam CandlePower/Seconds): Beam Candlepower Seconds is the measure of effective intensity of a light source when it is focused into a beam by a reflector or lens. Beam Candlepower Seconds is the effective intensity for a period of one second.

Bounce Lighting:
Bounced light is an indirect light source, where the actual light is pointed away from that which you wish to illuminate, and bounced off of a reflective surface back towards your subject. This can be achieved in flash photography with reflector panels, umbrellas, and even reflective surfaces such as a wall or ceiling. Bounced light is used when you desire a softer, less harsh light quality than is produced with direct lighting.

Bracketing:
When shooting, bracketing is taking several photographs of the exact same scene and setup with different exposure settings both above and below the target setting indicated by the flashmeter. As different brands of flashmeters vary in their readings for a .correct. exposure, bracketing both above and below the indicated settings will ensure that you get a properly exposed picture. If, for example, the indicated exposure for a setup is f5.6 with a shutter speed of 1/60 second, you can bracket for one stop less at f8, and one
stop more at f4.

Color Balance/Color Temperature (see also Kelvin):
The Color Temperature refers to the color of a light source, measured in Kelvin. The Color Balance refers to the relationship between the color of light and the film.

Contrast:
The contrast is the degree of difference between the dark and the light areas of a scene or photograph. High contrast photographs are a result of high contrast lighting, where there are sharp differences in the dark and light, and less in between. High contrast lighting can be achieved with both direct and bounced light that is not softened or diffused, but often reflected from a bright silver surface.

Depth of Field:
The depth of field refers to the nearest and farthest points in your photograph that are in focus in your shot. A lens can only focus on one single distance fully, but with a wide depth of field, areas both closer and further from that one point are relatively in focus as well. Stopping down to a smaller aperture increases the depth of field, and will result in more of the photograph being in focus.

Diffused Light:
Diffused light is softened light, with less shadows and more even coverage. A diffused light source is most commonly achieved by directing light through a translucent material, such as a diffusion shoot-through umbrella, a softbox, or a diffusion reflector panel.

Dynamic Range
Dynamic range is of special importance to digital capture. This is the ratio of the brightest tone to the darkest, and affects the scene, the camera, and the way the image is displayed.

EXIF

Fill Light:
In a lighting setup, the fill light refers to the light source which is used to fill-in. the shadows cast by the main light. This source can be a flash unit, or simply a reflector that is directed on the subject to illuminate the shadowed areas and lessen the contrast.

Filter/Gel:
A filter or gel for a flash unit is a thin piece of tinted or colored gelatin placed directly over the light source to alter the quality of the light.s output. Gels will physically change the color of the light, whereas filters will modify its quality. We offer color gels, warming filters, diffusion filters, UV filters, and neutral density filters.

F-stop:
An f-stop is a designation to indicate a camera’s aperture opening, and a flash unit’s power level. Our flash units are measured in power over a range of available f-stops, indicating the high or low power level setting of the unit. Each f-stop (shown on the back panel of our flash units) lets in twice as much light as the f-stop before it, and half as much light as the f-stop after it. Over a 5 f-stop range, the power is adjustable from Full down to 1/32 of the total power. For f-stops in relation to your camera’s lens opening, see aperture.

Highlight/Hot Spot:
Highlights or hot spots are very bright, well-lit and often overly lit areas in your setup, causing a very dense, dark spot on your negative. Hot spots appear when one area of your scene is overly lit, and can be avoided by diffusing or lowering the output of light on that area.

Hot Shoe:
A hot shoe is a u-shaped mounting point, usually found on the top of 35mm SLR cameras. This feature provides a slide-in mounting of small, battery operated flash units. In addition, it provides an electrical circuit connection which fires the flash when the shutter is tripped. If your camera does not have the necessary PC connection to wire our flash unit sync cord, you can purchase a hot shoe adapter piece, which fits in your hot shoe, and allows the sync cord to be plugged into your camera.

Lens Flare/Light Spill:
With ambient and studio lighting, when light is directed or refracted into the camera’s lens, this light is known as lens flare. Some photographers will allow light to be reflected in their camera’s lens for an intended glowing effect, but normally light spill is undesired. When using studio lighting to illuminate your subject, you can eliminate light spill by position your flash unit and accessories to not direct light back into your camera.

Main Light:
The main light in a lighting setup is the primary light used. This primary light source is typically the brightest in your setup, casting the most prominent shadows.

Manual Exposure:
Manual exposure is a camera mode which is non-automatic, and requires the photographer to set their own aperture and f-stop for each shot. This mode does not rely on the camera’s internal metering system, but requires you rather to take a reading with a separate flash meter to determine correct settings. When using external flash units, your camera should be adjusted manually.

Monolight:
The terms .monolight. and .flash unit. are often used interchangeably. A monolight is self-contained flash system that incorporates the power supply and flash head in one package. This term is used to distinguish these systemsfrom .power pack. systems where the power supply and flash head are separate and are connected using a heavy duty, custom cable. Monolights draw their power directly from standard wall outlets.

Recycle:
When you fire your flash unit, it releases all of the energy stored in its flash capacitors in order to emit the flash of light. Before you can fire the unit again, the capacitors must have time to recycle, or build up enough energy in the capacitors in order to fire again. AlienBee flash units boast extremely fast recycle times, which are lessened as you decrease the flashpower. On the X-Series X800 unit, for example, the unit may be used at full power and will recycle in under 1 second! Fast recycle times are important for rapid shooting, as you can take shot after shot without pausing to wait for your flash unit to keep up.

Shutter Speed:
Shutter speed is a term which refers to the length of time your camera’s shutter is open. As the shutter opens and closes to expose your film, the shutter speed measures in seconds the length that light is reaching your film. Obviously, the longer the shutter speed, the more light you are letting in. Very fast shutter speeds will allow you to stop action, but require a great deal of light.

Slave:
A flash unit is said to be a slave flash when it is set up to fire by detecting the flash from another (master) flash unit in a multi-light setup. This allows multiple light setups to be operated with only one light synchronized (wired) to the camera. As many slaves as necessary can be used in a set-up.

Sync:
The sync connection in a flash system connects to the camera body, either to a PC connector or through the hot shoe. This circuit is used by the camera to fire the flash at the precise moment that the shutter has fully opened and before it begins to close to successfully capture the full light burst from a flash set-up.

Through-The-Lens Meter (TTL):
A TTL meter is a light/exposure meter which is built into your camera, and takes light readings through the lens to determine the correct settings when in automatic mode. Often, this meter sends out a pre-flash or infrared sensor in order to detect the amount of available light. This signal may inadvertently trip your unit’s built-in slave tripper, and therefore can not be used with flash units.