How Light Is Used To Create Images-Fourth Update (2 of 4)

How Light Is Used To Create Images-Fourth Update (2 of 4)

by William Lulow

In the last article on “How Light Is Used To Create Images,” we talked about MODIFYING and controlling light in order to create images. Today, we’ll talk about the various types of light modifying tools we can use. Since the simple reflector is limited in its ability to provide the kind of light necessary for good, commercial portraits, it needed to be changed. Over the years, photographers found that they still needed to direct light toward their subjects, but that light was much better if it was soft. So, they tried to figure out what could make the light soft. And, they discovered that a large light placed fairly close to their subjects would give a very pleasing light. Manufacturers of photographic lighting equipment began making very large reflectors that were able to take large bulbs. Today, these kinds of light fixtures are sometimes referred to as “beauty dishes.”

They are large, very broad reflectors that are also fairly shallow. (The one pictured above is only 22” in diameter. But some were quite a bit larger.) They were of the theatrical variety in that they often took a fair amount of electricity to run and became very hot to handle. But, the science of these lights, in terms of the effect they had on the light they produced, made for nice, soft light that could be used to create great portraits. THE LARGER THE LIGHT SOURCE, THE SOFTER THE LIGHTING EFFECT.  This is one of the main ideas for portrait photographers. They need large light sources in order to provide the kind of light required for commercial portraits. (Notice how large some of these umbrellas are compared to the size of a normal human head).  Of course, smaller reflectors had their purpose as well. Photographers began to use them to add accents to highlight certain aspects of their subjects or the backgrounds. As manufacturing practices improved, they found that they could duplicate the effect of beauty dishes quite nicely by using large umbrellas that were made with reflective material inside them. Light from a bulb had to travel to the umbrella, bounce off it and then travel the remaining distance to the subject. This served very nicely to soften the effect of the light.

This photographic umbrella has a diameter of roughly six feet! It also has a black backing which prevents light from escaping through the material which would greatly lessen its effect.

Here is my large, photographic umbrella in use at the studio:

I actually began with an umbrella I had made especially for portraits. I went to an umbrella manufacturer and asked if they could make one with twice the normal number of ribs, because I noticed that on commercially available photographic umbrellas, many had 8 ribs. This meant that the distance the fabric was stretched between ribs made a straight line. This was very unsightly when reflected in the catchlights of the subject’s eyes. I also wanted a rounder light source. So, they made me an umbrella with 16 ribs instead of the normal eight. Today, the umbrella shown here has the required number of ribs to make the light source appear round, and was commercially available. It is also roughly 5.5 feet in diameter. I guess they took my requirements into account! This light is both very round and large enough to give the required softness to the light to provide great quality on my subjects. The coverage of this umbrella is so good that sometimes I can even use it with no fill-in. The one thing photographers need to be aware of is that because the light is BOUNCED, it needs to travel twice the distance to the subject. This lessens its intensity and needs to be compensated for by increasing its power or increasing the lens’ aperture. My lights produce enough power so that my usual studio exposure at ISO100 is f/11.

With all this about umbrellas and why they are used, comes the opposite idea of creating shadows purposely. This can be done effectively with what we call “raw” light. That is a strobe head aimed toward a subject without any diffusion or bounce qualities. This is how I like to use my accent lights. In order for the light produced by any kind of accent light to reproduce as white in the image, it should really be about one f/stop brighter than the main light you are using. In other words, if your main light is reading f/11, your accent lights should be reading f/16. Here is an example I always like to use of an EDGE LIGHT accent:

This EDGE LIGHT produced the white highlight on the subject’s face here. There was also a white reflector card used, camera left, to prevent the shadow side of the face from going completely black. This kind of accent light can be used in conjunction with a mainlight to produce certain highlights like the following:

In this image, notice the highlights on the subject’s hair. They were produced with an EDGE LIGHT positioned camera left behind her. This is what the light actually looks like:

These are using a different subject, but you can see the light that’s positioned by the background and aimed at the subject’s head, camera right. Also notice that it has no diffusion, but has a BARN DOOR attached to it to keep the light from spilling over too much toward the camera. In this case the “barn doors” are Roscoe Cinefoil attachments to the reflectors themselves. They are another way of “aiming” the light so that it will produce the highlights you want and keeping unwanted light off certain other areas. You can also use “gobos” to accomplish the same purpose and keep light from spilling where it is not wanted. Here’s the final image from a lighting setup like this:

The next article will deal with modern uses of light modifiers.