Some of your best flash pictures can be made with the flash unit off the camera. Holding the flash off the camera and above the lens tends 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. People are accustomed to seeing things lit 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, front lighting. Light from an angle can also be used to bring out the texture of a subject.

Indoors, two factors are important when determining the modeling and texture effects you will get: first, the surface of the subject itself; second, the way you light that subject. To illustrate these points, try photographing a Ping-Pong ball and a tennis ball together. When you use direct, front lighting, your picture records a two-dimensional visualization of height and width, but little of roundness, depth, or texture. When you light the balls from the side, both acquire the illusion of depth; however, only the tennis ball reveals texture. The Ping-Pong ball is much smoother and is almost textureless.

Now substitute a young child and an old person for the balls. With frontlighting, most of the lines and wrinkles in the old person's face will be minimized by the evenness of the light; however, when lighted from the side, almost every crease will become a shaded area and the ridges will be highlighted. Thus the texture of the old person's face is emphasized. The child, on the other hand, when side lighted, is still almost textureless just as in the case of the Ping-Pong ball.

LIGHTING RATIO

Lighting ratio can be considered as a measure of contrast. Lighting ratio refers to the combined intensity (at the subject) of the main and fill lights as compared to the intensity of the fill light alone; for example, both the main and fill light of equal intensity are shining on the subject. A reflected light meter reading is taken off an 18-percent gray card at the subject position that indicates there are 100 units of light falling on the subject. Now, with the main light turned off and the fill-in light still illuminating the subject, the reflected meter reading indicates there are only 50 units of light falling on the subject; therefore the lighting ratio is 2 to

1. Lighting ratio is usually expressed as the comparison of two light intensities, such as 1:1, 2:1,3:1, and so on.

The largest number in a lighting ratio indicates the most intense illumination at the subject position; for example, a 2:1 ratio indicates the most intensely lighted portion of the subject (highlights) is receiving twice the amount of illumination as the least intensely lighted portion of the subject (shadows). The light that produces the most intense illumination is called the main, key, or modeling light. The light that produces the least intense illumination is called the fill, or fill-in. A fill or fill-in light, as the name implies, fills in and softens the shadows produced by the main light.

Because a lighting ratio is a comparison of the combined main and fill light illumination intensities to the fill light illumination intensity alone, the fill light must be in a position so it completely illuminates the portion of the subject visible to the camera. This requires positioning the fill light close to the lens.

As a rule, 3:1 lighting is considered the best general lighting ratio for both black-and-white and color photography. This 3:1 ratio provides normal contrast between the highlights and shadows and produces good natural-looking photographs.

Some automatic electronic flashes allow you to control the output of light. When set in the manual position, you can adjust the light output by changing the intensity of the flash unit to 1/2, 1/4, 1/8, 1/16, and so forth. This allows you more control of flash-to-subject distance as well as aperture (depth of field) control.

Achieving the desired lighting ratio with an automatic flash unit where the flash intensity can be controlled is quite easy. To achieve a 2:1 ratio, you set both flash units at the same distance and at the same intensity (either full power, 1/2, 1/4, and so on). To achieve a 3:1 ratio, set both flash units at the same distance and set the main light flash at full power and the fill flash at one-half power. A 5:1 or even higher lighting ratio can be obtained by setting both flash units at the same distance and the main flash at full power and the fill flash at one-fourth power, and so on. In order to select a wider aperture to control depth of field, start by setting your main flash at one-half or one-fourth power and adjust your fill flash appropriately.

Adjusting lighting ratios by flash-to-subject-distance is another method to control lighting ratios. An easy way to calculate footage for a 3:1 ratio with two lights of equal intensity is to think of the full f/stops (2, 2.8, 4, 5.6, 8, 11, 16, 22, etc.) as distances in feet. Place the main light at the desired distance closest to one of the "f/stops," and place the fill light at the distance indicated by the next larger number; that is, 5.6 feet and 8 feet or 16 feet and 22 feet, and so on.

Another easy method to control the lighting ratios using an automatic electronic flash is to use the flash unit in the automatic mode. When set in the automatic mode, the flash-to-subject distance is not supercritical, and there is some leeway as long as the flash units are within their operating range.

To obtain a 2:1 lighting ratio, you simply have both flash units set at the same automatic setting and at approximately the same distance from the subject. For a 3:1 lighting ratio, use the same automatic setting and approximately the same flash-to-subject distances, but set the fill flash at twice the film speed as the film being used (main flash setting). For a 5:1 or even higher lighting ratio, use the same automatic setting and approximately the same flash-to-subject distance and set the fill flash at four times more than that of the main flash, and so on.

Any lighting ratio can be obtained when using an automatic flash unit. By controlling the power output intensity, adjusting the film speed setting, changing the main and fill flash distances, or a combination of the three, you can manipulate the lighting ratio easily to any ratio. As with any stage of photography, practice and testing with your camera and flash combinations in various situations produces the best results.