How Light Is Used To Create Images- III
by William Lulow
Note: This is the third article in the series and contains a bit of history.
In the old days, most studio photography was done with theatrical hot lights. And, they were just that…HOT. Flash has actually been around almost since the beginning of the photographic process in the early 1800s. Photographers used a mixture of potassium chlorate with other substances and ignited it in a flash bar to produce a brief, intense flash of light. Sometimes it was accompanied by a loud noise as well.
After that came the flash bulb which was a glass bulb that contained crumpled up aluminum in an environment of oxygen. It was ignited by an electric current produced from a battery. Today’s electronic flashes are made with a small flash tube that contains xenon gas that is ignited from an electric charge produced by modern batteries. It produces a short, bright flash of light.
In the past, it was difficult to synchronize the flash with the camera’s shutter. The camera had to be mounted on a tripod and the lens opened before the flash was ignited. Later, it was also hard to synchronize the flash with the shutter. There was a “B” (bulb) setting that delayed the opening of the shutter for a fraction of a second until the flash bulb reached its peak of illumination. Today, modern electronic flash units can be synched to fire instantaneously when the shutter opens.
It is important to understand the basics of artificial light before one begins to work with electronic flashes, but most people will just go out and buy a small flash unit that can fit in their camera’s hot shoe and just snap away. Flash units that are mounted onto cameras, or the built in flash units that accompany most modern cameras are limited in the kind of light they provide. The light comes from the same spot as the camera and produces a harsh, flat light that is basically only good for illumination, that is, to provide light when there is not enough ambient light to take a picture. It’s not really great for portraits.
As an aside, in our digital world, most cameras can take a picture when it is all but pitch black in the room. ISO speeds up to 64,500 are not uncommon. But with high ISO settings, some image quality suffers. I have shot events with my portable flash units at settings of ISO 1000 with no real loss of image quality. (I’m not blowing the images up that large, however. But, I’m still able to get decent 8×10 size prints).
If you want to begin to be creative with your use of light, you will need to purchase one or more units that can be operated OFF the camera. These will have to be mounted on light stands or placed in other positions around the studio or wherever you are shooting.
Most photographic studios today use a type of electronic flash that requires a flash generator and several “heads” mounted on light stands, all off the camera.
Here are some examples of large, studio electronic flash units. They are used in most large studios today:
These are the “packs.” They are flash generators which take electricity and turn it into a current that will flow through the flash “heads” below, and produce a short, powerful flash of light.
More about these units in the next article, but the best way to learn how to use these lights is by first beginning with regular incandescent “hot” lights (as I have said). I have detailed the placement of lights in other articles and you can refer to the archives in lighting for more information. I also re-post some of them from time to time. Then, using the same positioning, you can begin to develop a technique for shooting portraits with flash units.
Note: Any modern electronic flash unit can also be used with a softbox by using what is called a “speed ring” that allows the softbox to be mounted to the lights themselves. Most flash “heads” also have holes that hold photographic umbrellas as well.