Camera and Lens

CHAPTER 3 Camera and Lens Barbara Morgan, Martha Graham in “Letter to the World”. © Barbara Morgan, Willard & Barbara Morgan Archive/Time Inc. is the licensee. CAMERA AND LENS Modern cameras are extremely sophisticated devices, in- ways of controlling the exposure on the film and various volving computer-designed lenses, complicated electron- devices for handling film and controlling focus of the lens. ics, and construction from high-tech materials. In spite of These tasks may be performed automatically by the cam- this complexity, all cameras are basically the same, pro- era or manually by manipulation of the controls. An un- viding a light-tight container for photosensitive materi- derstanding of the basic parts and operation of the camera als—film—and a lens to form an image of the subject and lens will clarify the role that the more sophisticated matter on the film. The other parts of the camera provide electronic devices play in the functioning of the camera. The Camera Film advance Camera body Viewfinder Aperture Lens Shutter Focusing device Film Camera. This is a simple camera, but it contains all the parts necessary for complete control in making photographs. Camera Body. Light-tight enclosure Viewfinder. Shows an approximate view of Shutter. Shields the film from the image until protecting the film from unwanted exposure to the part of the subject that will appear in the the shutter release is pressed, when it opens for light. Opens to allow loading of film. image on the film and may include a method a measured amount of time (the shutter speed) Lens. Forms an image of the subject matter on for checking the focus of the image. controlled by a knob, lever, or ring. Controls the film. Aperture. An opening adjusted by means of exposure on the film. Focusing Device. Moves the lens in and a dial, lever, or ring with marked f-stop Film Advance. A lever or knob that moves out to select the subject distance that will be in numbers. Controls the amount of exposure on the film forward for the next photograph. focus. the film. Format Size An important influence on the technical quality of a pho- compactness makes them popular as snapshot cameras. tograph is the format size—the size of the image on the The Minox—famous as a “spy” camera—produces an 8 ϫ film. The rendition of detail and fineness of grain gener- 11mm image on specially packaged film. The Minox is a ally increase with increasing format size. Film format is precision instrument, but because of the small image size, also discussed on page 16. great care must be taken to get images of any clarity. Miniature-format cameras are generally of the Advanced Small-format cameras normally use 135 (35mm) film Photo System (APS) design, with a special cartridge film and produce a 24 ϫ 36mm image. The original Kodak In- giving a 16 ϫ 24mm format. Because of the small size of stamatic cameras and other cameras using 126 film are the negative, these cameras are generally used where ex- also small format, with a 28 ϫ 28mm image. Small-format treme enlargement of the image is not necessary. Their cameras offer compactness and ease of handling. With 39 CHAPTER 3 dim, it must be shielded from extraneous light with a housing or a dark opaque cloth while viewing. Viewfinder/Rangefinder Camera In a viewfinder camera, viewing is done through an eyepiece with its own simple lens, having the advantages of lighter weight, quieter operation, less vibration, and a brighter view than comparable cameras with other viewing systems. Since the viewfinder is not in the same position as the camera lens, it shows a slightly different view of the subject, called parallax error. Most viewfinders are adjusted to give the correct subject inclusion for distant subjects. For closer subjects, the different viewpoint of the viewfinder begins to be noticed, causing part of the subject seen in the Format Size. Counter-clockwise from bottom center; Miniature-Format APS Camera, Small-Format 35mm Camera, Large-Format 4 ϫ 5-inch View viewfinder to be cut off in the film image. In some Camera, Medium-Format 120 Camera. viewfinder cameras the framing lines change as the camera is focused at different distances to show correct fram- modern films and lenses, 35mm cameras give technical ing. Others may have additional framing lines for close quality good enough for most photographic purposes. distances. Even when the subject inclusion is corrected, Medium-format cameras use 120 or 220 roll film and pro- parallax causes an image difference due to the different duce several different image sizes depending on the point of view. The rangefinder is a focusing aid included model, including 6 ϫ 4.5cm (usually called the 645 for- in many viewfinder cameras (see page 42). Viewfinder/ mat), 6 ϫ 6cm (2 1/4 ϫ 2 1/4 inches), 6 ϫ 7cm, 6 ϫ 8cm, rangefinder cameras are available in a variety of format and 6 ϫ 9cm. Medium-format cameras are useful when a sizes. larger image size and a reasonably compact camera are de- sired. Modern medium-format cameras are typically expensive and designed for professional use, though over the years many simple medium-format snapshot cameras have been produced. Large-format cameras produce images 4 ϫ 5 inches, 8 ϫ 10 inches, and larger and usually use sheet film. Large- format sizes require less enlargement for viewing and produce sharper images, more detail, and finer grain. However, as the format size increases, the camera be- comes larger and more difficult to handle. Film and pro- cessing costs also increase accordingly. Large-format cameras are used when the highest-clarity images are de- sired and the camera size and relatively slow operation are not a disadvantage. Viewfinder-type Camera. Camera Types Single-Lens Reflex Camera In a single-lens reflex (SLR) camera, the image from the lens is deflected to Cameras are often categorized by the method used for a ground glass by a mirror, which swings out of the way viewing the image. Two basic methods are used to see when the shutter release is operated. The image on the what subject matter will be included in the image on the ground glass is reversed right to left, since it is a mirror film. One is looking through a viewfinder, which is an op- image. Many single-lens reflex cameras use a pen- tical device included in the camera body separate from taprism, a specially designed prism that is located the lens that produces the image on the film. The other is above the ground glass and shows a correctly oriented direct viewing of the image formed by the camera lens. image through an eyepiece. To be visible, this image must be formed on an actual sur- Single-lens reflex cameras offer the advantage of face, usually glass with a roughened surface, called viewing the actual image that will fall on the film. Fo- ground glass. Several designs make use of a ground glass cus can be seen in the eyepiece. Interchangeable lenses in the viewing system. Since the ground glass image is are common with this type of camera, since any changes 40 CAMERA AND LENS as with viewfinder cameras. They tend to be bulkier be- Pentaprism cause of the separate viewing and taking lenses but are Ground glass quieter and less expensive than comparable single-lens reflex cameras. Twin-lens reflex cameras are less generally available today than in past years and are usually medium format. If you would like to move in to medium- format photography, but can not afford the current equip- ment, look for a used TLR, which may be very reasonable Swinging in price. mirror View Camera The view camera is a direct-viewing sys- Single-Lens Reflex Camera. SLR cameras do not have parallax error. The tem. The ground glass is placed in the exact position the only difference between the eyepiece view and that on the film is that the film will occupy and then moved out of the way when the edges of the subject are cut off by most SLR viewing systems. This is known film, enclosed in a special holder, is inserted into the cam- as viewfinder cutoff and results in slightly more of the subject ap- pearing on the film than is seen in the viewfinder. era. The image seen on the ground glass of a view camera is upside-down, just as the image on the film will be. The lens and back of a view camera can be tilted or to the image can be seen directly. Disadvantages are the swung to alter the focus or shape of the image, an advantage extra noise, weight, and bulk caused by the moving mir- when photographing buildings or tabletop still life subjects. ror and shutter types needed to provide reflex viewing Since the image is viewed directly, focus can be checked by and the blacking out of the viewfinder while the shut- placing a magnifier on the ground glass. An opaque cloth ter is open. Single-lens reflex cameras are generally must be draped around the ground glass for viewing the dim available in 35mm and medium-format sizes. image. Disadvantages of the view camera are its bulk— making a tripod or other support necessary—and its rela- Twin-Lens Reflex Camera In a twin-lens reflex (TLR) tively slow operation. View cameras are normally 4 ϫ 5-inch camera, two identical lenses are mounted on the camera. format or larger and accept sheet film in holders.

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