Source

Ambient

Ambient light is existing natural or artificial light present in any environment. Ambient light can be subdivided into four major categories: ~ Daylight ~ Tungsten ~ Fluorescent ~ Firelight.

Daylight

Daylight is a mixture of sunlight and skylight. Sunlight is the dominant or main light. It is warm in color and creates highlights and shadows. Skylight is the secondary light. It is cool in color and fills the entire scene with soft diffused light. Without the action of skylight, shadows would be black and detail would not be visible. White balance is usually calibrated to daylight at noon (5500K). When images are recorded at this time of the day the colors and tones reproduce with neutral values, i.e. neither warm nor cool.

Tungsten

A common type of electric light such as household bulbs/globes and photographic lamps. A tungsten element heats up and emits light. Tungsten light produces very warm tones when used as the primary light source. Underexposure occurs due to the lack of blue light in the spectrum emitted. Digital cameras can be set to automatically adjust the white balance to correct the color cast from light sources of different color temperatures or this can be set by the photographer by choosing either a white balance setting or creating a customized white balance setting (see Color Correction and Filtration > Color accuracy in camera).

Fluorescent

Phosphors inside fluorescent tubes radiate light after first absorbing ultraviolet light from mercury vapor emission. The resulting light from most fluorescent tubes produces a strong green cast that can be difficult to correct and is not apparent to the human vision. If used as a primary light source the results are often unacceptable due to the broad flat light and the strong color cast. Daylight balanced fluorescent tubes and compact fluorescent lamps or CFLs are available and these are increasingly being used as a photographic light source (see Lighting on Location > Halogen or daylight balanced fluorescent lamps on location).

Firelight

Light from naked flames can be very low in intensity. With very long exposures it can be used to create atmosphere and mood with its rich red tones.

Tungsten (non-domestic) There are many variations of non-domestic tungsten light sources used in photographic, film and TV studios. They all fall in to two major categories, floodlight and spotlight. The majority have a color temperature of 3200 – 3400K. A simple floodlight would have an output of 500 watts and a basic focusing spotlight around 650 watts. Professional spotlights come with barn doors and nets. Barn doors are metal flaps used to control the shape and quantity of light falling on the subject. Nets are pieces of wire gauze of varying densities that reduce the quantity and alter the quality of the light by diffusing the light at its source. Similar items used to create the same effect when using a floodlight are known as cutters (shape and quantity) and various diffusion material (quantity and quality). See ‘Studio Lighting’.

Flash (studio) The main differences between location and studio-based flash are size, cost and output. Studio flash is physically larger, costs a great deal more and produces a far greater output of light. The precise color temperature between different flash units may vary but the majority have a color temperature similar to daylight (5500 – 7000K). Despite the names, swimming pool, soft box, fish fryer, honeycomb etc., these are really only large or smaller versions of a diffuse light source. The use of an open flash (direct light to subject without diffusion) will give a similar effect to a spotlight. Most brands have focusing capabilities and the range of attachments available for tungsten exist in one form or another for use with flash. See ‘Studio Lighting’.

Rodrick Bond

Activity 2

Research the cost and availability of photographic light sources (tungsten and flash), stands and associated equipment. Research any low cost lighting alternatives not specifically designed for photographic needs. Compare their output, measured in watts, and cost.