Using A Second Light In Your Lighting Setup

Note: With the recent article I published about using one light as a means to get started with the study of lighting, I thought I would re-publish this article of what a second light would do to your images.

Using A Second Light In Your Lighting Setup

by William Lulow

In the previous blog article, I wrote about shooting with one light. Although this is the right way to begin using artificial light, and perhaps the ONLY way to begin, it should be clear that just one light creates a series of shadows in a photograph where no information is visible. That’s also what we get when we use the sun as a primary light source. The natural progression would be to try to add some detail where the shadows create just blacks. This is the main reason for adding a second light. There are a couple of other reasons as well. 

Normally, the second light in a lighting arrangement will add some more detail, fill in shadow areas or provide some interesting highlights. More information could take the form of making the background lighter, thereby adding detail to the photograph. It could be added to the foreground, thereby lightening the shadows. Or, it could be added from the sides to create different highlights and effects.

This image was lit with just one light placed above the camera and to the left of it. Note the deep shadows on the opposite side. If I wanted to make those shadows more transparent, to show more detail, I would add a second light, a fill-in light to that side:

In this shot, you can now see some detail in the shadow areas because I have set up a second light to fill in the shadows. Note that I have still preserved the characteristics of the mainlight. If I wanted the shadows even more transparent, I could move the fill-in light half the distance closer to the subject:

Here, the shadows are even lighter than the one above, but the effect of the mainlight is still visible. The light was moved even closer to the subject (half the distance again). Moving the fill-in light source further back or closer varies its intensity. So you can decide just how much detail you want to show. You can achieve the same kinds of effects by varying the power settings on your electronic flash unit.

Once you set up your mainlight, you would add a second light, or a FILL-IN light in the front to lighten shadow areas a bit. The second light should come from the opposite side of the camera. So, if your main light is high and to camera left, the fill in light should be low and to camera right. The thing that is most important to remember is that the second light should be less intense than the first (main light). If you have two lights of the same intensity, you will wind up with conflicting shadows which give the image an unnatural look. One good way to make sure that the intensity of the second light is less than the main light is to have bulbs of different wattages. If you use a 500watt photoflood for your main light say, use a 250watt bulb for your fill in light. Or, if you are using flash, make sure your main light is on full power and your fill in light on half power. This will ensure that the fill-in light will be about one f/stop less than your main light and will not over-power it. If the power of your light sources was the same, another way to make sure the fill-in light was less intense would be to move it back from the subject twice the distance of the mainlight. That would yield about one f/stop less intensity. There are other ways of keeping the LIGHT RATIO (relation of the mainlight to the fill-in light) the same. For instance, if your mainlight was bounced into an umbrella and on full power (from a studio flash), your fill-in light should also be diffused but moved twice the distance away from the subject to make it one f/stop less. Or, you can use a light meter or flash meter to determine intensities of both lights.

If you are trying to create HIGHLIGHTS the procedure is kind of the opposite. The highlight source needs to be one f/stop BRIGHTER than the mainlight in order to register white in the image. Here is an example:

In this portrait, the highlights on the hair look white. The lights that produced them were used straight or “raw”, they were not bounced or diffused. The mainlight was bounced into my large umbrella and so was kept one f/stop less than the highlights.

I like to begin lighting lessons, especially with more than one light, by using hot light bulbs because you can readily see the effect of position, intensity, angle, etc. WITHOUT TAKING A PICTURE!  This forces you to THINK about what you are doing when you set up your lights. There are many photographers who set up a multiple light set without really thinking about what they are doing. Those results will always be disappointing.

This is one of my typical portraits made with a mainlight, a fill-in light and a highlight (accent light) to light the hair. Note that the mainlight is coming from the right, the fill-in light from the left and much lower, so that it creates a bit less light on the left side of the face, thus giving it some depth. The highlight is coming from the back and left of the subject and it is set to one f/stop brighter than the mainlight. The highlights are registering white against the background. In this image, I have also put some light on the background to give it a gradient tone.

The reason for adding extra light is to provide more detail or to separate the subject more from the background. These techniques always make for more interesting images and also make them stand out more from simple snapshots. So you need to decide how much information you want to show and how dramatic you want your image to be. Then you can add your second light with purpose. 

If you are working outdoors in natural light, I try to put the sun BEHIND my subjects to create natural highlights. This usually puts faces in shadow so they would need to be filled in with some type of lighting tool. I sometimes carry a 16×20″ white card to lighten up some shadow areas, I will sometimes use the camera’s built-in flash in a pinch, but most times I use an external flash on a light stand that is battery powered to provide the necessary fill-in light. This will provide just enough light to fill in the shadow areas. Here is an example:

Here, the sunlight provided a highlight on the subject’s hair and shoulders while a fill-in light on a stand lightened up the shadows enough to provide overall illumination. I will publish a piece about using flash fill-in lighting outdoors in a subsequent blog.