The job of the evidence photographer is to strengthen and sharpen the visual properties of photographs by carefully controlling factors such as camera angle, distance, and lighting. However, the accuracy of evidence documentation may be limited by the inadequacies of an under-trained photographer, compounded by the inherent limitations of the photographic medium itself. Vision is one of the tools the human brain uses to experience the world around it. Taking into account all the factors related to the basic principals of vision, a person trained and experienced in crime-scene investigation may perceive a scene differently from a person trained only in photography. An example of one of the differences between vision and photography is the instantaneous sensitivity of the human eye versus the cumulative receptor. The photograph can show less, similar, or more detail than the human eye may have under the same circumstances. One way to achieve proper perspective is to show a subject along with corresponding spatial relationships. This means that an image must provide enough visual clues in order for the observer to gain a sense of depth or scale. The bottom line is that mistakes made in the representation of proper perspective lead to mistakes in visual accuracy in the analysis of images.