Continuous Lighting Vs Flash Lighting

Continuous light sources are often used in studio photography instead of flash.

When it comes to photography in the studio or in other types of indoor settings, you can seldom rely purely on ambient light to shoot a properly exposed picture. In these cases, use controlled, artificial lighting. There are two main types of controlled lighting: continuous lighting and flash lighting. Each has its own advantages and disadvantages, and the recommended use of each method depends on a variety of factors.

Continuous Light

As its name implies, continuous light sources deliver a continuous output of light. In general terms, any light bulb is a source for continuous light; however, for photography and cinematography purposes, camera operators use specialized sources of continuous light. An advantage of continuous sources is that you can observe the actual light falling on the subject as you set the lights. The main disadvantage is the heat they produce, especially so-called "hot lights." This can be uncomfortable for live subjects under long periods. More recent models of continuous light sources do not generate as much heat, though.

Modifying Continuous Light

When using continuous light, employ light modifiers such as reflectors, soft-boxes, umbrellas and scrims for softer, more diffuse light suitable for certain types of photographs, such as portraits. On the other hand, you can modify continuous light sources to direct hard light with sharply defined shadows. Modifiers greatly extend the utility and variety of effects possible with continuous light sources, but they also represent an added expense.

Flash Lighting

Electronic flash units--specifically those available on-camera--are easy to use, portable and reasonably priced. However, they tend to produce harsh lighting, which, if not properly used, can lead to flat, unattractive pictures. You can attach modifiers to the flash unit, which soften the harshness and lead to more aesthetically pleasing shadows and depth, according to the book "Sculpting With Light." However, the degree to which you can modify on-camera flash is more limited than with continuous light sources.

Strobe Lighting

A third category that is seldom mentioned is strobe lights. They essentially combine characteristics of both continuous and flash lighting. Strobe lights feature a flash tube alongside a continuous modeling light that simulates the effects of the actual light that will fall on the subject during flash exposure. The modeling light's power is very low compared to that of the flash tube, so it doesn't generate much heat or have any effect on the photograph's final exposure.

Conclusion

In studio photography, on-camera flash is a valid way of taking photographs, but most of the time it results in flat, harshly illuminated photographs, even with modifiers to make the light more diffuse. Continuous light sources offer more flexibility and usually result in more aesthetically pleasing pictures, but most light sources can give off too much heat for certain situations. Strobe lighting combines the best of both lighting modes and, if used correctly, can lead to truly spectacular images.

Tags: light sources, continuous light, continuous light sources, much heat, actual light, aesthetically pleasing