K – abbreviation for kelvin.
K14 – the chemical process for developing Kodachrome slides.
kilobyte (kb) – a digital storage capacity of 1,024 bytes. The word means “1,000 bytes”.
kbps – kilobytes per second. Relates to the speed at which video- or audio information is transferred from a server to your browser. Slow connections have a low kbps value, so if the user has a slow connection, you limit the bandwidth of your video or audio by setting a maximum kbps value. This will influence the way in which compression is applied to your video/audio, for instance, a low rate will result in a lower quality while a broadband connection can have better quality and therefore a higher bit rate.
kHz – kiloHertz (thousands of Hertz). See Hertz. one kiloHertz (kHz) is 1000 Hz. For example, the common audio sample rate of 44100 Hz can also be expressed as 44.1 kHz. Equivalent to 1,000 cycles per second.
KS – Kodak Standard perforations. Compared to BH perforations, larger in size, and with rounded corners for extra strength. used primarily for release prints.
kelvin – a system or scale for measuring temperature. absolute zero is 0° kelvin or -273° c. The ‘color’ of white light is expressed in degrees kelvin; 6500k for daylight.
kelvin or kelvin scale – the visible light spectrum is scientifically described in terms of color temperature, and is measured in degrees kelvin (°k).
key – 1. A general adjective denoting importance. 2. Also called key source or key cut. A signal that can be used to electronically “cut a hole” in a video picture to allow for insertion of other elements such as text or another video image. The key signal is a switching or gating signal for controlling a video mixer which switches or mixes between the background video and the inserted element. The composite effect created by cutting a hole in one image and inserting another image into the hole. This is selective substitution of picture information from one source with picture information from a different source. 3. A video special effect in which the level of a video signal is used as a switch which allows luminance keyers use the amplitude of the monochrome portion of the signal, while chroma keyers use the amplitude of a specific color or hue. Most printed material is inserted into video using luminance keys, while picture information is inserted using chroma keys.
key bus – a video switcher cross-point bus used to select key sources (hole cutters) and/or key fills. Signals available to the key bus are typically the same sources and fills that are supplied to the other switcher crosspoint buses plus additional external key sources and fills.
key channel – a channel of a digital picture manipulator that is used for manipulating key signals while the corresponding key fill video is manipulated by another channel. 2. Also called “alpha channel”. A black-and-white video signal that can be added to the existing channels of a video signal (YUV or RGB). Normally used to determine parts of a video image that can be replaced by other content.
key follow – see envelope tracking.
key frame – or keyframe. 1, An effect that has been stored in memory, similar to a snapshot photograph. individual key frames can be strung together to create an overall key frame effect, which is similar to animation. 2. A frame from an animated sequence, at which a significant animation event or change takes place. In computer animation, the animator defines the keyframes and the computer generates the intermediate frames (process called ‘tweening’). 3. The state of an object explicitly defined in one frame. The state includes object’s position, rotation, size, shape, etc., which can be all specified together in a single frame or separately in different frames. Animation is achieved by giving different values for a particular parameter (such as position) in two different frames. Computer then automatically calculates (interpolates) the change over time. 4. In addition to basic keyframe animation, more specific methods to propagate change over time have been developed (although they all use keyframing in one way or another). 4a. Shape interpolation, shape of an object may change over time by interpolating between keyshapes. The keyshapes usually have to have the same topology, i.e. they must contain the same number of control points in the same order. In practice this means that the different shapes are first copied from the original and then altered. Today there are algorithms which allow even topologically different shapes. 4b. Cluster animation, one method to do shape interpolation is to divide the surface of the object into groups and animate them. These groups are often called clusters. this way we do not need to have different versions of the object. 4c. Deformation, shape of an object may be changed by another object (deformer) or by a specific ‘force field’. Deformation is animated by moving the deformed object and the deformer in relation to one another. For example, a snake can be made to crawl by pulling it through a flat sine-curve. 4d. Skeleton, is what the name implies. Human(oid) figures are easily animated by building a skeleton that matches the figure. After animating the skeleton the figure is attached to it, and voilá!, the figure walks – legs bend, hips rotate, etc. 4e. Inverse kinematics, instead of animating the skeleton bone by bone, with inverse kinematics you can just animate the ends of the skeleton (feet, fingers, etc.) and the intermediate joints follow according to the given rules. 4f. Dynamic simulation, real world phenomena (such as friction) is imitated by using dynamic simulation. This is achieved by attaching physical properties (such as mass) to objects and manipulating forces that produce motion in objects over time. 4g. Forces, include gravity and winds – local (fan) and global. Force intensity, direction, etc. may be animated. 4h. Collision detection: normally, 3d objects pass through each other freely. With collision detection they don’t. This is achieved by defining obstacles for an object. For example, to bounce a ball down the stairs you first select the ball and then select the stairs as an obstacle. Then drop the ball – it detects the impacts and behaves accordingly.
key frame effect – an overall effect consisting of a series of snapshots called key frames. When the key frames are replayed, the machine (switcher, DPM, etc.) automatically and gradually dissolves from one key frame to the next. A process called ‘in-betweening’ defines what happens between key frames. The result is a moving animation effect.
key-framing – is the process of assigning values to parameters at specific moments in time to create an animation. The most important parameters to be key-framed are the transformations of models (objects), the camera, and lights. Thus all objects in the scene can be scaled (resized), rotated and transformed (moved) the course of the animated sequence. The lights can be translated and rotated. The rendering camera can also be transformed and rotated. The surface material characteristics of an object, the colour or intensity of a light, the zoom ratio of the camera, and even the geometry of objects can be key-framed. The 3d application interpolates between the key-frames, creating the frames in between the key-frames when rendering.
Interpolation can occur in both space and time. animation curves are used for full control.
key grip – or key. The key grip works closely with the director of photography and the gaffer to sculpt the desired look of a film by diffusing and cutting the light. The key grip is also in charge of camera movement whether on a dolly, camera crane or mounted on the hood or bumper of a vehicle.
key light – also called “main light.” The principal source of light on a subject or a scene, usually in reference to a studio light. the key light is generally the brightest light on the subject, or the one that will have the greatest overall effect on the image. It is normally positioned slightly off center and angled to provide shadow detail. See back light, fill light, three-point lighting.
key numbers – see “edge numbers.”
key tone – 1. the “k” in CMYK, representing black in an image. 2. an image’s dominant or most important tone, often the middle tone between black and white.
keyboard – a set of keys or levers, arranged in order of ascending pitch, which enables a piano, organ or synthesizer to be played by hand.
keyboard scaling – a function with which the sound can be altered smoothly across the range of the keyboard by using key number as a modulation source. Level scaling changes the loudness of the sound, while filter scaling changes its brightness. A tone can be changed evenly along a keyboard.
keyboard tracking – see envelope tracking.
keycode – a machine-readable code printed along the edge of the camera negative film (outside the perforations). It provides data e.g. about the film type, the name of the manufacturer and the film stock. Additionally, a reference number for the first frame on the film is given in order to match the film with a particular position of an edl/cut list. In transmissions of digital video, keycodes can also be used to replace or supplement timecode information. Technically, keykode refers to the machine readable bar code next to the edge numbers that the manufacturer placed on the film; over time it has become synonymous with edge numbers or footage numbers.
keykode numbers – Kodak machine-readable key numbers that include a 10-digit key number, identification code, film code and off-set in perforations, pre-printed on the edge of negative film used for editing and negative conforming.
keyer – an electronic circuit that creates a control signal to control a video multiplier based on selective information contained in a video signal.
keystone – the effect of projecting an image onto a surface that is not perpendicular to the axis of the projecting lens. Parallel lines tend to converge in the direction where the surface is closer to the lens.
keystone error – the trapezoidal distortion of a square-cornered image due to the optical effect of the projection device not being located in its proper position in respect to the screen.
keystoning – 1. the result arising when the film plane in a camera or projector is not parallel to the view or screen, leading to a trapeze shaped distortion of a projected image when the projector is not directed perpendicular to the screen. On a stereoscopic image, where the cameras are ‘toed-in’ so that the object of interest coincides when viewed, there can be some mismatching of the outlines or borders of the two images. Techniques like corner pinning can be use to help correct this. 2. Perspective distortion from a flat object being shot by a camera at other than a perpendicular angle. Nearer portion of object appears larger than farther part.
kicker – 1. a side or back light often near lens height used to rim faces and model profile shots. 2. a light used to provide an additional highlight or accent on a subject. Also called a “hair light”, it is placed behind the subject to create a glamorous halo effect on the hair or a rugged-looking highlight on the cheek. Helps separate the subject from the background.
kickoff – the start of production or principal photography.
kinescope – also called “kine.” A method of making a film copy of a television program in the days before the existence of video recorders. A movie camera was aimed at a specially designed television monitor. Before video recorders were invented this was the only means of recording tv programs. Many kinescopes are now over 40 years old and have the potential to outlast videotapes that were created much later.
Kodak™ – 1. More commonly-used name of the Eastman Kodak Company™, a U.S. technology company that manufactures and sells cameras and photography products. 2. A name some give to their cameras, as in “I
put film in my Kodak”.
kodak neutral test card – also known as the “gray card,” a kodak neutral test card is an 8″ x 10″ (20 cm by 25.5 cm) card, about 1/8″ thick, that is uniformly gray on one side. The gray side reflects precisely 18% of the white light that strikes it (corresponding to the calibration of a reflected-light meter). It is uniformly white on the other side, which reflects 90% of the light.