EXISTING LIGHT

Existing light photography, sometimes called available or natural light photography, is the making of pictures by the light that happens to be on the scene. This includes light from table, floor and ceiling lights, neon signs, windows, skylights, candles, fireplaces, automobile headlights, and any other type of light that provides the natural lighting of a scene - except daylight outdoors (moonlight is considered existing light). Existing light is that type of light found in homes, in offices, in the hangar bay, in the chapel, in the club, in sports arenas, and so on. Outdoor scenes at twilight or after dark are also existing light situations.

Photography by existing light produces pictures that look natural. Even the most skillfully lighted flash picture may look artificial when compared to a good existing light photograph. With existing light photography, the photographer has an opportunity to make dramatic, creative pictures. Existing light allows the photographer greater freedom of movement because he is not burdened with extra lighting equipment. Subject distance, when not using flash, has no effect on exposure, so you can easily photograph distant subjects that could not otherwise be photographed using flash or some other means of auxiliary lighting. With existing light you can make pictures that you could not make with other types of lighting.

For example, flash may not be appropriate during a change of command ceremony or chapel service. Not only might the flash disturb the proceedings, but it may not carry far enough to light the subject adequately.

Fluorescent Lighting

Indoor scenes illuminated by fluorescent lights usually appear pleasing and natural in real life. However, color pictures of these same scenes will often have an overall color cast that makes them look very unnatural. Fluorescent light is deficient in red light and emits primarily blue and green light. Most color pictures made without a filter under fluorescent light also are deficient in red and have an overall greenish appearance. When it is used correctly, fluorescent light does have some advantages over other types of available light. A room illuminated by fluorescent lamps is usually brighter and more evenly lighted than a room illuminated by tungsten lamps. This higher level of light makes it easier to get enough exposure for your existing light photography and helps record detail that might have been lost in the shadow areas with other types of existing light.

When you are photographing people, fluorescent lighting often causes dark shadows under the eyes of the subject. This effect causes the eyes to appear dark and sunk in.

Nighttime, Outdoor Pictures

Outdoor night scenes usually include large areas of darkness broken by smaller areas of light from buildings, signs and streetlights. Pictures of outdoor scenes are quite easy to make because good results are obtainable over a wide range of exposures. The use of short exposures emphasizes well-lighted areas by preserving the highlight detail, while the shadow areas become dark due to underexposure. Long exposures help retain the detail of the dark areas, while highlight detail is lost as a result of overexposure.

Large, dark areas in night scenes will make it difficult for you to make accurate exposure meter readings from your camera position. You will get the best meter reading results when you take closeup readings of important scene areas.

At night you can make color outdoor pictures using either daylight or tungsten-type films. Pictures made on daylight film will have a warm, yellow-red appearance.

Those made on tungsten film will have a colder more natural look. However, both films provide pleasing results so it is a matter of personal preference.

A good time for you to make outdoor night color pictures is just before it gets completely dark At this time, some rich blue (or even orange) is in the sky. This deep color at dusk gives a dramatic background to your pictures. Neon signs, streetlights and building lights make bright subjects for your pictures.

ELECTRONIC FLASH LIGHTING

In situations in which there is little or no light available, a portable, electronic flash unit is an invaluable piece of photographic equipment. With fast films and long exposures, you may be able to shoot existing light pictures - provided your subject remains still long enough. Although you can certainly get better lighting control with elaborate photographic lights, the simplicity and portability of electronic flash is unbeatable.

Electronic flash provides an excellent source of artificial light for exposing black-and-white and color daylight film. Light from an electronic flash unit (strobe) is characterized by its softness, short duration and color balance, approximating that of daylight.

When you measure the amount of light that actually reaches an objector scene, a numerical value is obtained that can be converted directly into a flash guide number. The numerical value is the light output rating of an electronic flash unit measured in beam candlepower-seconds (BCPS) or more correctly, effective candlepower-seconds (ECPS).

Every electronic flash unit is assigned a guide number as a measure of its light output or power. The higher the guide number, the greater the light output.

Correct exposure with electronic flash depends upon the following four factors: l The power or light output of the flash unit . The ISO speed of the film used l The flash-to-subject distance l The tistop used

Shutter speed is not a factor since the time of exposure is governed solely by the duration of the flask.

Notice we always speak of flash-to-subject distance, never camera-to-subject distances. With all types of artificial illumination (the same as with

Figure 11-15. - Exposure scale on a flash unit (automatic mode).

sunlight), the only consideration is the amount of light reflected from the subject. The distance between the camera and the subject has no bearing on exposure. When the flash is used off the camera, the basic f/stop is still calculated with the flash-to-subject distance.

Automatic Electronic Flash Units

Most electronic flash units can be operated in an automatic exposure mode. An automatic flash unit eliminates the need to determine the correct f/stop for each flash-to-subject distance, providing the subject is within the flash distance range of the flash.

On the front of an automatic flash unit, a sensor reads the light reflected from the subject that is produced by the flash. When this sensor is satisfied as to the amount of light received, it automatically shuts off the flash. The closer the subject is to the lamp, the quicker the sensor shuts off the light.

Some automatic electronic flash units allow you to select two or more apertures to control depth of field. To determine an f/stop in the automatic mode, you can use the calculator dial located on the unit. When you match the indicator to an ISO film speed number on the dial (fig. 11-15), the f/stop to be used within a minimum and maximum distance is indicated. Once an f/stop is selected and set, it is a constant factor regardless of the flash-to-subject distance, providing it is within the flash distance range of the unit. This feature allows a photographer to move closer to or further away from the subject without having to calculate an f/stop for each change of flash-to-subject distance.

Figure 11-16. - Exposure scale on a flash unit (manual mode).

When the flash unit is in the manual mode, the f/stop must be changed every time the flash-to-subject distance changes. A scale on the flash unit (fig. 11-16) indicates the proper f/stop to use for the various distances. To determine the flash-to-subject distance for on-camera flash, focus on the subject and read the distance directly from the focusing ring on the camera.

Single Flash

You will produce the majority of your indoor photographs with a single flash unit. Numerous reenlistments, frocking and promotion ceremonies are conducted indoors where the lighting conditions are unfavorable for available light photography. There are various methods in which a single flash can be used to produce high-quality professional photographs which distinguish you from the amateur snapshooter.

On-Camera Flash

A flash technique commonly used is that of the flash unit attached to the camera, in synchronization with the shutter, and aimed directly at a subject. An advantage of having your flash unit attached to the camera is it gives you the chance to capture the unexpected - the truly candid shot. When spontaneity sparks the action and quick camera handling is a must, the fewer pieces of equipment you have to worry about or handle, the better. Rather than two pieces of gear (the camera and the flash), you have only one - the camera with the flash attached to it. However, this technique usually produces objectionable shadows behind the subject.

To help reduce the harshness of shadows, plain some diffusion material, such as a white handkerchief, cheesecloth, or frosted cellulose acetate, in front of the flash. Keep in mind that diffusion reduces the intensity of the light. Therefore, the exposure must be increased accordingly if you use the manual mode on the flash unit.

Off-Camera Flash

You will make some of your best flash pictures with the flash unit off the camera. When you hold the flash off the camera and above the lens, it will tend to throw the shadows down and behind the subject. This is a good way to minimize distracting background shadows that occur when a subject is standing close to a wall. A flash held high above the lens, either left or right, makes the viewer less conscious of the flash illumination.

We are accustomed to seeing things lighted from above, and by placing the flash above the subject, it closely resembles the lighting of the sun or ceiling lights.

Light that is far enough off the camera to illuminate the subject from an angle produces modeling or roundness. This type of light creates the illusion of a third dimension - depth - and is more pleasing to the viewer than the two-dimensional flat effect you get with direct frontlighting. Angled lighting also is used to bring out the texture of a subject.

Bounce Flash

One of the best methods to illuminate a subject or scene with a single flash unit is to use bounce flash. There will be times when you will want a very soft light in order to lessen the tonal range between highlights and shadows and to soften harsh background shadows. You can achieve this soft lighting by bouncing, or reflecting the flash off a light-colored surface. By doing so you are changing the narrow spot of light from a flash unit into a wide, diffused area of light.

Most bounce flash pictures are made with the light directed at the ceiling, either above the photographer or above the subject, or somewhere in between. You can produce a silhouette effect by bouncing the flash off the ceiling behind the subject. To accomplish this, aim your flash unit so most of the light bounced off the ceiling falls on the background behind the subject and calculate the exposure for the background.

For the flattest bounce light, try bouncing the light off a wall behind the camera. With this lighting you will have practically no shadows. Here you will have to

calculate your exposure based on the flash-towall-to-subject distance.

"RED-EYE"

An effect that may appear with direct flash is "red-eye." Red-eye occurs in pictures of people and animals when the. flash is used close to the optical axis of the lens and the subject is looking at the camera. It is caused by light reflecting from the blood vessels at the back of the eye. The darker the room is, the stronger the effect will be because the pupils of the eyes will be dilated. Red-eye can be avoided easily by your moving the flash away from the lens optical axis. Also, you can minimize the effects of red-eye by turning up the room lights.