PARALLELISM and DOF T
here are several factors that influence depth of field. One of them is the distance from the subject to the camera. As the subject moves away from the camera, depth of field increases. Conversely, as the subject moves closer to the camera, depth of field decreases. This is true for any focal length lens. When doing macro photography or when using a long lens to capture subjects fairly close to the camera, the distance factor is very important in determining how much of the subject is in focus. Consequently, the angle the camera is held relative to the plane of the sub-
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ject becomes very relevant. To illustrate this point, look at the picture below and notice the depth of field. Most of the butterfly is sharp except the ends of the antennae and the furthest tips of the hind wings (red arrows). The reason this happened was because the camera was angled relative to the plane of the wings. As you can see in the graphic on the next page, the plane of the digital sensor was oblique to the plane of the butterfly’s wings. Therefore, over the surface of the sensor the distances to the subject varied. The dashed green lines represent
