Angle of Reflection = Angle of Incidence

The physical law of light states that "the angle of reflection is equal to the angle of incidence." The angle of incidence is the angle that light is striking a surface. The angle of reflection is the angle that the light is reflected, or bounced (figure 1).

To simply illustrate this seemingly complicated law, we begin this reflector demonstration by positioning a 32" x 42" soft box and light at 90 degrees to the right of the subject. This will be our "main" light (figure 2).

We set the ice bucket in the middle of the main light area (figure 3).

We are using this highly reflective ice bucket so that you can easily see how the light and reflections look. We don't necessarily think that this is how you should light this product if you were trying to take a photo of it, we are using it to show you how this lighting concept works.

As you can see from the results, the main will give you a nice even highlight that wraps around the ice bucket and gradually tapers off (figure 4).

To give the left side of the ice bucket some more detail in the shadow area, we positioned a white 42" LiteDisc on the left side. The photo term for this is a " bounce fill."

We set-up the bounce fill 90 degrees to the left of the subject in a similar position as the "main" light. So, if the reflection is equal to the angle of incidence, then light aimed directly at a reflector will bounce directly back (figures 5 and 6).

Or for you techie people, if the incident of light is 90 degrees, than the angle of reflection will be 90 degrees.

As you can see, the reflection on the left is a mirror image of the highlight on the right (figure 7).

Here is our first illustration with the "main" only and the second photo with the "main" and "bounce fill" for comparison (figures 8 and 9).

To further demonstrate this basic principle, we set the "main" at approximately 45 degrees to the ice bucket, and positioned it farther away (figures 10 and 11). We kept the subject in the middle of our light spread area.

Here is the results photo. You can see that the highlight is moved more to the front of the ice bucket. The highlight is smaller because we moved the main light farther away from the subject (figure 12).

Our next step is to add our bounce fill. We set the white 42" reflector on the LiteDisc holder to left of our subject at about a 45-degree angle (figures 13 and 14).

In our results, we see the effect of the bounce fill on the subject. We now have soft, open light with both of our light sources coming from the front of the subject (figure 15).

In figure 16, we see the comparison of all the final images. You can easily see the results of each of our steps.