Cinematography (from Greek: kinesis κινησις (movement) and grapho γραφω (to record)), is the discipline of making lighting and camera choices when recording photographic images for the cinema. It is closely related to the art of still photography, though many additional issues arise when both the camera and elements of the scene may be in motion.
The camera does what a human eye does. That is, it creates perspective and spatial relations with the rest of the world. However, unlike one's eye, a cinematographer can select different lenses for different purposes. Variation in focal length is one of the chief benefits of such an advantage. The focal length of the lens in particular, determines the angle of view and, therefore, the field of view. Cinematographers can choose between a range of wide angle lenses, "normal" lenses and telephoto lenses, as well as macro lenses and other special effect lens systems such as borescope lenses. Wide-angle lenses have short focal lengths and make spatial distances more obvious. A person in the distance is shown as much smaller while someone in the front will loom large. On the other hand, telephoto lenses reduce such exaggerations, depicting far-off objects as seemingly close together and flattening perspective. The differences between the perspective rendering is actually not due to the focal length by itself, but by the distance between the subjects and the camera. Therefore, the use of different focal lengths in combination with different camera to subject distances creates these different rendering. Changing the focal length only while keeping the same camera position doesn't affect perspective but the angle of view only. A Zoom lens allows a camera operator to change their focal length within a shot or quickly between setups for shots. As prime lenses offer greater optical quality and are "faster" (larger aperture openings, usable in less light) than zoom lenses, they are often employed in professional cinematography over zoom lenses. Certain scenes or even types of filmmaking, however, may require the use of zooms for speed or ease of use, as well as shots involving a zoom move.
Like in photography, the control of the exposed image is done in the lens with the control of the diaphragm aperture. As to properly expose, the cinematographer needs that all lenses be engraved with T-Stop, not f-stop, so that the eventual light loss due to the glass doesn't affect the exposure control when setting it using the usual meters. The choice of the aperture also affects image quality (aberrations) and depth of field (see below).
Depth of field and focus
Focal length and diaphragm aperture affect the depth of field of a scene — that is, how much the background, mid-ground and foreground will be rendered in "acceptable focus" (only one exact plane of the image is in precise focus) on the film or video target. Depth of field (not to be confused with depth of focus) is determined by the aperture size and the focal distance. A large or deep depth of field is generated with a very small iris aperture and focusing on a point in the distance, whereas a shallow depth of field will be achieved with a large (open) iris aperture and focusing closer to the lens. Depth of field is also governed by the format size. 70 mm film has much more depth of field for the same focal length lens than does 35 mm. 16 mm has even less and most digital video cameras have less depth of field than 16 mm. But if one considers the field of view and angle of view, the smaller the image is, the shorter the focal length should be, as to keep the same field of view. Then, the smaller the image is, the more depth of field is obtained, for the same field of view. Therefore, 70mm as less depth of field than 35mm for a given field of view, 16mm more than 35mm, and video cameras even more depth of field than 16mm. As videographers try to emulate the look of 35 mm film with digital cameras, this is one issue of frustration - excessive depth of field with digital cameras and using additional optical devices to reduce that depth of field.
In Citizen Kane, cinematographer Gregg Toland used tighter apertures to create very large depth of field in the scenes, often rendering every detail of the foreground and background of the sets in sharp focus. This practice is known as deep focus. Deep focus became a popular cinematographic device from the 1940s onwards in Hollywood. Today, the trend is for more shallow focus.
To change the plane of focus from one object or character to another within a shot is commonly known as a rack focus.
Aspect ratio and framing
The aspect ratio of an image is the ratio of its width to its height. Beginning in the 1910s, motion pictures settled on a ratio of four to three (four units wide to three units high). Often written as 4:3, this ratio may be reduced to 1.33:1 and this aspect ratio is commonly known as 1.33. The introduction of sound-on-film narrowed the aspect ratio briefly, before the Academy ratio of 1.37 was introduced in 1932 by means of thickening the frame line. For years, cinematographers were limited to this shape of image, but in the 1950s, thanks to the unanticipated popularity of Cinerama, widescreen ratios were introduced in an effort to pull audiences back into the theater and away from their home television sets. These new widescreen aspect ratios granted cinematographers a wider frame within which to compose their images. Many different proprietary photographic systems were invented and utilized in the 1950s to create widescreen movies, but one dominates today: the anamorphic process, which optically squeezes the image to photograph twice the horizontal area to the same size vertical as standard "spherical" lenses. The first commonly used anamorphic widescreen format was CinemaScope, which used a 2.35:1 aspect ratio, although it was originally 2.55:1. CinemaScope was used from 1953 to 1967, but due to technical flaws in the design and its ownership by Fox, several third-party companies, led by Panavision's technical improvements in the 1950s, now dominate the anamorphic cine lens market. Changes to SMPTE projection standards altered the projected ratio from 2.35:1 to 2.39:1 in 1970, although this did not change anything regarding the photographic anamorphic standards; all changes in respect to the aspect ratio of anamorphic 35 mm photography are specifically correlative to camera or projector gate sizes, not the optical system.
After the "widescreen wars" of the 1950s, the motion-picture industry settled into 1.85:1 (which is a cropped version of 1.37:1) as a standard for theatrical projection in the United States and the United Kingdom. Europe and Asia opted for 1.66:1 at first, although 1.85:1 has largely permeated these markets in recent decades. Certain "epic" or adventure movies utilized the anamorphic 2.39:1.
In the 1990s, with the advent of high-definition video, television engineers created the 1.78:1 (16:9) ratio as a mathematical compromise between the theatrical standard of 1.85:1 and television's 1.33:1, as it was not physically possible to safely create a television tube with a width of 1.85:1. Until that point, nothing had ever been originated in 1.78:1. Today, this is a standard for high-definition video and for widescreen television.
Most likely the single most important aspect of cinematography is lighting. Light is necessary to create an image exposure on a frame of film or on a digital target (CCD, etc). The art of lighting for cinematography goes far beyond basic exposure, however, into the essence of visual storytelling. Lighting contributes considerably to the emotional response an audience has watching a motion picture. The control of light quality, colour, direction and intensity is a major factor in the art and science of cinematography.
One aspect of cinematography that strongly separates it from still photography (aside from having a moving subject) is the ability to move the camera, which represents the audience's viewpoint or perspective, during the course of filming. This movement plays a considerable role in the emotional language of film images and the audience's emotional reaction to the action on the screen. From the most basic movements of panning (horizontal shift in viewpoint from a fixed position; like turning your head side-to-side) and tilting (vertical shift in viewpoint from a fixed position; like tipping your head back to look at the sky or tilting your head down to look at the ground) to dollying (placing the camera on a moving platform to move it closer or farther from the subject), trucking (placing the camera on a moving platform to move it to the left or right), craning (moving the camera in a vertical position; being able to lift it off the ground as well as swing it side-to-side from a fixed base position), and a combination of all of the above. Cameras have been mounted to nearly every imaginable form of transportation.
Most cameras can also be handheld, that is the camera operator literally holds the camera in their hands and moves from one position to another while filming the action. Personal stabilizing platforms came into being in the late 1970s through the invention of Garrett Brown, which became known as the Steadicam. The Steadicam is a body harness and stabilization arm that connects to the camera that allows the operator to move naturally while completely isolating the movements of their body from the movements of the camera. After the Steadicam patent expired in the early 1990s, many other companies began manufacturing their concept of the personal camera stabilizer.
The first special effects in the cinema were created while the film was being shot. These came to be known as "in-camera" effects. Later, optical and digital effects were developed so that editors and visual effects artists could more tightly control the process by manipulating the film in post-production. For examples of many in-camera special effects, see the work of early filmmaker Georges Méliès.
Role of the cinematographer
In the film industry, the cinematographer is responsible for the technical aspects of the images (lighting, lens choices, composition, exposure, filtration, film selection), but works closely with the director to ensure that the artistic aesthetics are supporting the director's vision of the story being told. The cinematographers are the heads of the camera, grip and lighting crew on a set, and for this reason they are often called directors of photography or DPs.
Directors of photography make many creative and interpretive decisions during the course of their work, from pre-production to post-production, all of which affect the overall feel and look of the motion picture. Many of these decisions are similar to what a photographer needs to note when taking a picture: the cinematographer controls the film choice itself (from a range of available stocks with varying sensitivities to light and color), the selection of lens focal lengths, aperture exposure and focus. Cinematography, however, has a temporal aspect (see persistence of vision), unlike still photography, which is purely a single still image. It is also bulkier and more strenuous to deal with movie cameras, and it involves a more complex array of choices. As such a cinematographer often needs to work co-operatively with more people than does a photographer, who could frequently function as a single person. As a result, the cinematographer's job also includes personnel management and logistical organization.