This glossary contains alphabetical listing of studio photography related terms & their definitions.

Angle of Incidence ::. Light striking a surface is called “incident light.” It becomes “reflected light” when it reflects from the surface. The “angle of incidence” is the angle at which the incident light strikes the surface, and is measured from a line that is perpendicular to the surface (called the “normal”).

Artificial Light Films ::. Is color transparency films designed for use with light sources with a lower color temperature than daylight. Usually these are provided for use with studio tungsten lighting which has a color temperature of 3200K (Kelvin).

Boom Arm ::. A metal pole attached to a lighting stand and that holds a flash head at the end. A counterbalance weight is also usually used. This is used to get the flash closer to the subject as well as over or under it.

Back Projection ::. Projection system often used to create location backgrounds in the studio.

Bounce Head ::. A feature of electronic flashguns that have a head that point’s upwards so that the light can be bounced off a ceiling to soften and spread the light.

Bounced light ::. Is the light that is reflected off a surface before reaching the subject. Flash is often bounced off a ceiling or card to soften the result. Reflectors can be used to bounce light into shadow areas to reduce contrast.

Barn doors ::. Folding metal flaps that attach to the front of a studio light to control the light spill and prevent light straying on to areas where it’s not wanted.

Charging time / Recycling Time ::. This time is measured between the flash and the point of time when the ready indicator is lit again. According to the DIN standard the ready indicator can be lit as soon as 70% of the full charge is reached. For uniform results, however, the broncolor ready indicators light up only when 100% of the selected charge is reached. Consequently recycling times quoted by broncolor are 100% recycling times.

Color temperature ::. The color temperature is a measure for the color of a light source. The color is compared to the light emitted by a glowing object. Average daylight has a color temperature of 5500K (K=Kelvin, a measure for the absolute temperature). Lower values produce a yellowish cast; higher cooler temperatures produce a bluish cast. Most film materials are balanced for 5500K.Generally the flash color temperature slightly depends on the power setting of the flash unit. The values specified are valid for full power.

Capacitor ::. Unit for storing and releasing a pulse of electricity Stores electrical energy supplied by a power source and can discharge it more rapidly than the source itself. Used in flash equipment, providing reliable bulb firing even from weak batteries, and supplying the surge needed for electronic flash tubes.

Cookie ::. A flat board, like a flag, but full of irregular holes used for creating a pattern of shadows when put in front of a light.

Cooling System ::. Indicates whether the flash head incorporates a fan or ventilation system to ensure it doesn't’t overheat. This can be important on power full units.

Dedicated Flash ::. An electronic flash head that coordinates with the camera's exposure system, and also sometimes with the camera’s focusing systems. Dedicated flashes may, among other things, automatically pick up the loaded film's ISO, set the camera shutter speed to X-sync, and "tell" the camera when its ready to fire.

Diffused Light ::. Is a light that has lost some if its intensity by being reflected or by passing through a translucent material a typical example of such a light source would be a soft box in a studio. Diffusion softens light, eliminating both glare and harsh shadows, and thus can be of great value in photography, notably in portraiture.

Direct Light ::. Light falling directly from a source onto the subject.

Electronic flash ::. Portable or studio lighting that’s created by an electronic discharge through a recycling gas-filled tube.

Effective flash duration ::. It is the interval between the time when the light intensity first reaches 50% of its peak value until the point of time when it has decayed to that same value. The effective flash duration t 0.5 is more customary and is often used in brochures and data sheets. However, when movements have to be frozen with short flashes it should be remembered that the flash is still illuminating at half its maximum intensity after the specified t 0.5 time. In these cases t 0.1 should be considered. Both values are interconnected by the following rule of thumb: t 0.5 is 3 times shorter than t 0.1.

Flash range ::. An electronic flash has a maximum distance that it is capable of illuminating. There’s also usually a close point where it will start to become too bright and overexpose the subject. The distance from the closest to the furthest point that it can illuminate is the flash range. The range can be increased by using a faster film or more sensitive CCD, and reduced by diffusing the light source using ND filters or material. The range quoted is usually based on using ISO 100 film or a CCD with equivalent sensitivity. APS cameras are, for some reason, quoted using ISO 200 film.

Focusing screen ::. Ground glass screen fixed to the camera at the image-forming plane, enabling the image to be viewed and focused.

Flash Sync Socket ::. A socket on the camera used to plug-in an electronic flash gun cable so that the flash can be triggered at a distance from the camera.

Flash sync speed ::. Is the maximum shutter speed that can be set when using electronic flash. You can use shutter speeds below this setting but ones above will make some of the picture dark because the shutter would have partially closed before the flash had fired.

Fill-in Light ::. Light used to illuminate the shadow areas of a scene. A secondary source of light used to balance contrast in the subject.

Flash bulb ::. Old type of flash light that ignited by simple battery/capacitor system and used once.

Front Projection ::. Method of projection which allows you to combine a figure in a studio with a previously photographed background scene. The image is projected from the camera position onto a special reflective background screen.

Flash Duration ::. The light intensity is not constant throughout the duration of the flash. At the beginning the intensity is high and gradually decays towards zero as the end of the discharge is approached. Since this shape shows no obvious end of the light pulse 2 definitions are described in ISO Standard 2827: ‘effective flash duration t 0.5’ and ‘total flash duration t 0.1’.

Floodlight ::. Artificial light source with a dish shaped reflector and a 125-500+ watt tungsten filament lamp producing evenly spread illumination over the subject.

Fresnel-lens ::. A condenser type lens used on a spotlight to gather the rays of light coming from a light source and then directing them into a narrow beam.

Flag ::. This has two meanings. 1: It can be a large black cloth on a frame used on a shoot to keep light out of part of the composition. 2: In the cutting room it is a small piece of tape attached to a shot in a roll and used exactly as you would use a bookmark. The flag sticks out the side of the roll, making it easy to find that shot again quickly.

Gobo ::. Also called cutter or flag - An opaque panel used to block light from selected areas on the subject or from entering the camera lens.

Guide Numbers and f –numbers ::. Contrary to Joules these figures are a direct indication for the quantity of light reaching the object. The guide number is the product of the f - number and the distance and is applicable for reflectors which are small compared to the distance to the object. A typical application is portable flash guns. In studio situations, however, the light sources are often large compared to the distance so that the guide number is not constant. For studio applications it is more practical, therefore, to quote the f-number to be expected at typical working distance.

Gelatin Filters ::. Filters cut from dyed gelatin sheets and held in front of the lens or studio light.

High Key ::. A scene with delicate tones or pastel colors.

Hot Spot ::. Often undesirable concentration of the central beam of a flood or spotlight on the subject.

Incident Light ::. The light falling on a subject.

Incident-Light Reading ::. The measurement of light falling on the subject using a meter with a 180° diffuser cone positioned over the light sensor. This type of meter reading is not affected by the subject’s reflectivity so can often be more accurate.

Interchangeable Backs ::. If the camera has interchangeable backs you can change a film mid-roll so you could shoot color and black & white within seconds of each other. This is also useful if you have several users using a camera - each could have there own film back. It’s also good to record specific subjects on the same roll of film. For example you’re out walking and you could take flowers on one and landscapes on the other. Many medium-format cameras have the option of changing format with different backs. You could, for example shoot 6x7cm, 6x4.5cm and 35mm from the same camera using three different backs. Polaroid backs are also available for many cameras. This means you could shoot a Polaroid print and instantly check lighting, composition or exposure and then replace with the conventional film.

Interchangeable Lenses ::. If the camera has interchangeable lenses you have more flexibility because the lens detaches from the camera allowing it to be replaced by a different one. Most 35mm SLR cameras and many medium-format cameras have interchangeable lenses.

Interchangeable Viewfinder ::. Having an interchangeable viewfinder increases your scope to shoot from low down using a waist-level finder or to enable program exposure using an AE head. There are also options with magnifying hoods. Many medium format cameras have this feature, but only a couple of 35mm SLR’s do.

Infrared Remote Control ::. The Servo infrared remote control allows the photographer to control the power pack functions from the camera. This is helpful in adjusting the flash power and assessing the lighting effect by means of the modeling light. If the power packs are ceiling mounted IR remote control is essential.

Infrared triggering ::. The IR wireless triggering system replaces sync cables, eliminating the danger of tripping over the cable and causing damage to the camera. The IR triggering system is especially valuable where flash units are ceiling mounted or in cases where the lights have to be set up in the public. For this last application, broncolor units offer the possibility to switch off the photocell and trigger on infrared signals only. This avoids other persons triggering the flash unit with their hand held flash guns.

Joules / Watt seconds ::. Joules and Watt seconds are two names for the same thing. They describe the energy content of the storage capacitors in a flash unit. If a flash unit has a storage capacity of 300 Joules it can supply the power to light a 300W lamp for one second or a 300’000W lamp for 1/1000 of a second. However the number of Joules or Watt seconds gives no information about the quantity of light reaching the object to be photographed since it does not take account of electrical losses between flash capacitors and flash tube, efficiency of tube and reflector, reflector angle etc. Furthermore, the Watt second rating cannot easily be checked by the end user.

Kelvin (K) ::. Measurement of color temperature named after the scientist Lord Kelvin.

Key Light ::. Main light source that may cast predominant shadows.

Low Key ::. A photograph that comprises predominantly of dark or monotone colors.

Lighting Ratio ::. It’s the ratio of the light brightness difference on the subject, when comparing between the key-light and other fill-light sources. A ratio of about 3:1 is normal for color photography.

Main Light ::. A primary source of light responsible for the deepest shadows in the subject.

Modeling light ::. A light that is positioned close to an electronic flash so you can roughly preview the effect of the flash before taking a photo. Usually supplied with studio flash although a few on-camera guns have a strobe to assist.

Mono-bloc Flash ::. A studio flash unit that has its flash tube and charging circuitry all contained within the head.

Multiple Flashes ::. A flash technique where you fire the flash several times to increase the exposure allowing a smaller aperture to be selected. It can also be used for special effects; the most common being strobe like effect, following the swing of a golfer or the flapping wings of a nocturnal bird. It can also be used to light the same subject in several positions in the frame - to allow a multiple exposure effect.

Open flash ::. Where the shutter is held open and the flash is fired manually. This allows you to fire a smaller powered flash several times to ensure either a large area is covered or a single area receives enough exposure – a technique known as painting with light.

Photoflood ::. A bright tungsten bulb with a color temperature of around 3400K that is sometimes used in portrait studios. Most studio photographers prefer the convenience of electronic flash.

Quartz-iodine lamp ::. Compact tungsten filament lamp designed to maintain its color temperature and light intensity throughout its working life.

Reflected Light Reading ::. An exposure reading that measure from the camera position with the metering sensor pointing towards the subject. This is the system used by most through-the-lens systems or with handheld meters that haven’t got an white Inver-cone over the sensor. The angle in degrees is usually quoted.

Recycling Time ::. It is the amount of time a flash head takes for it to recharge between flash firings is the recycling time.

Reflections ::. Rays of light which strike a surface and bounce back again. Specular reflection occurs on even, polished surfaces; diffuse reflection occurs on uneven surfaces, when light scatters.

Rim Lighting ::. Lighting in which the subject appears outlined against a dark background. Usually the light source is above and behind the subject, but rim- lit photographs can look quite different from conventional backlit images, in which the background is usually bright.

Sync Lead ::. A cable that’s used to connect a flashgun to a camera and trigger it as the camera’s shutter fires.

Synchro-Sun ::. A term used to describe a combination of sunlight and flash light, where flash is used as a fill in.

Snoot ::. A conical tube that fits over a studio light that gives you more control over the light beam and forms a small circular patch on the subject. Often used as a hair light on portrait photography.

Soft-Box ::. A box with a diffuser panel that attaches to the front of a flash to give soft even light. Any visible highlights such as catch lights in eyes, reflections in silverware will be neat and square. Bigger ones give more surrounded and even light but absorb more light so are best used with powerful flash heads.

Side Lighting ::. Light striking the subject from the side relative to the position of the camera. It produces shadows and highlights to create modeling on the subject.

Studio Camera ::. Term given to a large format 12 x 15 inch camera on a wheeled stand.

Strobe light ::. Low power electronic flash that can fire repeatedly at regular, controlled intervals.

Spotlight ::. Artificial light source using a fresnel lens, reflector, and simple focusing system to produce a strong beam of light of controllable width.

Synchronized Flash ::. A method of synchronizing flash light duration with the maximum shutter opening. Synchronize is to cause a flash unit to fire at the same time as the camera shutter is open.

Slave Unit ::. A flash accessory, also known as a slave cell that’s used to fire another flash remotely so that multiple flash set ups can be arranged without cables and all synchronized with the camera’s shutter.

Total Flash Duration (t 0.1) ::. Is the interval between the time when the light intensity first reaches 10% of its peak value until the point of time when it has decayed to that same value. The sharpness of a picture taken of a moving object with a given t 0.1 is comparable to the result obtained with daylight and a shutter speed of that same value.

Tungsten Light ::. Incandescent light from a tungsten filament heated by an electric current.

UV coating ::. Similar to daylight, flashlight contains a certain amount of UV radiation. To avoid fluorescent effects broncolor flash tubes or protective glasses are equipped with a filter coating eliminating UV radiation and matching the color temperature of the Xenon gas to that of the average daylight.

Zoom head ::. An electronic flashgun feature that allows the flash coverage to be adjusted. Flashguns are usually designed to cover the same angle as a standard lens, so when a wide angle lens is used you may find the edges of the frame are darker. A zoom head pulls closer to the flash tube to widen the angle and extends to throw the flash light out at a more concentrated angle.