PHOTOGRAPHS

Photographs convey realism, permitting us to show our readers exactly what something looks like. They are highly persuasive because readers tend to trust the exactness of what is presented.

Unlike illustrations, which can be easily modified to eliminate unnecessary details, photographs present all visible elements. Consequently, a photograph should be "composed" in a way that directs the reader's eye to the principal point of interest. This requires that as much unnecessary clutter as possible be eliminated. Cropping may be employed to eliminate distracting details and to keep the photograph relatively simple.

Figure 2: Crash Test Dummies. Crash test dummies save lives by predicting human physics in auto accidents. Example

Tips for Using Photos Ensure that the photograph has a central point of interest and that the angle of the photograph aids understanding. Be sure that the photograph has sufficient contrast and is in proper focus. Obscure background details by adjusting the depth of field. Establish the size and proportion of a photographed object by using scales or by including objects in the photograph that permit scale comparisons.

Photographs taken extremely close up or extremely far away may be difficult for readers to grasp because they lack perspective. In these instances, we should print a scale beside the photograph or place a familiar object on or near the item being photographed.

Photographs of geologic features are especially difficult to interpret unless the photograph includes a vehicle, a person, or some other familiar object that permits a scale comparison.