Tuesday, April 26, 2011
Master The Family Of Angles
This fundamental aspect of lighting will help you figure out how to light anything, anywhere, anytime
Breaking The Inverse Square Law?
Did it alarm you to read that the camera that sees the direct reflection will record an image “as bright as the light source”? How do we know how bright the direct reflection will be if we do not even know how far away the light source is? We do not need to know how far away the source is. The brightness of the image of a direct reflection is the same regardless of the distance from the source. This principle seems to stand in flagrant defiance of the inverse square law, but an easy experiment will show why it does not.
Figure 5 has a mirror instead of the earlier newspaper. Here we see two indications that the light source is small. Once again, the shadows are hard. Also, we can tell that the source is small because we can see it reflected in the mirror. Because the image of the light source is visible, we can easily anticipate the effect of an increase in the size of the light. This allows us to plan the size of the highlights on polished surfaces.
Now look at Figure 6. Once again, the large, low-contrast light source produces softer shadows. The picture is more pleasing, but that is not the important aspect. More important is the fact that the reflected image of the large light source completely fills the mirror. In other words, the larger light source fills the family of angles that causes direct reflection. This family of angles is one of the most useful concepts in photographic lighting. We will discuss that family in detail.
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