Wide-Angle Lenses

Figure 1-34.–Angle of view. In figure 1-34, the diagram shows the different angles of view you can expect from several common focal-length lenses used with 35mm SLR cameras. Table 1-4 can be used in selecting lenses for one film format that provides the same angle of view produced by another film format and the lens focal-length combinations. To use this table, select the lens for one film format that provides the same angle of view produced by another film format and focal-length combination. Example: The angle of view of a 360mm lens on a 4x5 camera is 19 degrees. To match the angle of view approximately with a 35mm camera, a 105mm lens is needed. The normal focal-length lens (50mm) for a 35mm camera provides an angle of view of 40 degrees (width). You can see from the table that the normal focal-length lens for a medium format camera (2 1/4” x 2 1/4”) is an 80mm lens because it provides approximately the same angle of view (38 degrees). TYPES OF LENSES There is a large variety of lenses available for most hand-held cameras on the market today. These lenses are used for different photographic applications. The types of lenses you may use in the fleet are as follows: wide angle, ultra-wide angle, rectilinear, macro, normal focal length, telephoto, and variable focal-length, or zoom, lenses. Wide-Angle Lenses Anything less than 40mm in focal length (for a 35mm camera) is considered a wide-angle lens. Again, we are speaking of the lens focal length as it applies to 35 mm cameras. A wide-angle (short focal length) lens is designed to take in a large view and is indispensable when working in confined spaces or when you want to cover a large area. Wide-angle lenses have their own qualities, causing apparent, repeat, apparent, distortion and foreshortening of perspective, so objects close to the lens appear large, while background objects diminish in size dramatically. Many photographers choose a 28mm lens for their 35mm camera wide-angle lens. This is partly because this focal length allows the typical wide-angle effects without introducing apparently distorted images, such as bent walls. As well as providing a wider field of view, wide-angle lenses also produce great depth of field at all apertures. Short-focal-length lenses do not, as is often believed, actually change perspective. The close view- points allowed by wide-angle lenses can cause perspective effects that appear distorted but are perfectly natural ways of seeing objects at close range. A wide-angle lens magnifies features nearest the camera To fill the frame when photographing people with a wide-angle lens, you must move in close. This causes a distorted view. But wide-angle lenses can be used when special effects are desired, such as deliberate distortion, when exaggeration of features or when surrounding areas add to the viewer’s understanding of the subject. A lens hood, or lens shade, is an important accessory for any lens. It is especially important with a wide-angle lens. Strong light can easily cause flare when reflected internally between the elements of the lens, and unless you take proper precautions by using a lens hood, your pictures may be spoiled. Sometimes you are able to see flare or ghosting in the viewfinder, but more often than not, it is not visible to the human eye, and it only shows up on the processed film. Another precaution to take with wide-angle lenses concerns filters and other accessories attached to the 1-32