Digital Video Techniques

... Related Terms

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A-B roll--two video sources played simultaneously with the intention of mixing.

analog video formats--VHS, S-VHS, VHS-C, 8mm, Hi-8, 3/4-inch Umatic, Betacam, Betacam-SP

analog v. digital formats--analog is a continuous stream of information; digital is a series of discrete signals positioned closely together to appear as if continuous.  (See graphic.)

.asf--video file type

audio sampling rate and bit depth--in order to get the best quality audio for your video files, if you have a choice, choose 44,100 for the sample rate, stereo, and 16-bit (CD quality).

.avi--Audio-Video Interleave (file type).  These are generally larger than MPEG files.  PCs should be able to view either type.  (MPEG is Mac-compatible, whereas AVI files are not.)

bandwidth--the capacity of a network for transferring a quantity of data within a given time

bit rate--the number of bits transferred per second.  Higher bit rate produces smoother video motion.

blue screen/green screen--a solid-color blue or green screen used as the key color in compositing.  Everything that is blue (or green) is removed from the original video image and another video image replaces the areas of solid blue (or green).

broadcast formats--(1) NTSC (National Television Standards Committee), used primarily in North America, Japan and the Philippines, has a frame rate of 30 (29.97) frames per second and 525 lines.  (2) PAL (Phase Alternating Line), used primarily in Western Europe, Australia, Southeast Asia and South America, has a frame rate of 25 frames per second and 625 lines.  (3) SECAM (Sequential Couleur Avec Memoire), used primarily in France, Russia, Eastern Europe and Central Asia, also has a frame rate of 25 frames per second and 625 lines.

camera angles--(1) high angle, looking down on the subject--gives the viewer dominance, (2) straight-on angle--everyone is on equal footing ... most common shot, (3) low angle, looking up at the subject--gives the subject dominance.

camera moves--(1) zoom in or push:  draws the viewer into the shot making the main subject larger which forces the viewer to focus on that aspect of the shot.  (2) zoom out or pull:  makes the subject smaller, causing the viewer to consider surrounding activity.  (3) rack focus:  when a shot starts out of focus and slowly comes into sharp focus.  It can be used as a transition, and is often used to suggest the passage of time.  (4) pan left/right:  provides the viewer with more information about the scene or location.  The camera tripod does not move, only the camera itself.  (5) tilt up/down: provides more scene information from a vertical point of view.  Again, the camera tripod does not move.  (6) dolly in/out:  in this case the camera is physically moved closer to, or farther away, from the subject.  This movement tends to be used more by professionals than the zoom.  It approximates our own human way of viewing scenes.  A shot obtained with a moving camera continuously reveals new perspectives, emphasizing space and depth. (7) truck left/right:  a very common move used to follow talent.  (8) arc:  when the camera is rolled on a curving path around an object.  This shot works well in advertising products, etc.

camera shots--(1) wide shot (ws) or extreme wide shot (ews):  view from a distance, giving perspective; it is used to establish location; it is too wide to capture any details.  (2) medium shot (ms):  somewhere between a long shot and a close-up; used to provide more information about what the action is, where it is taking place, and who is involved.  (3) close-up (cu):  principal subject appears large on screen, dominating the shot; involves the viewer; heightens tension.  (4) extreme close-up (ECU):  an extremely tight shot of a subject, providing great detail.  (5) over-the-shoulder shot:  view of the subject framed by another subject's shoulder and back-of-the-head in the foreground.

capture--to record data such as audio, video, or still images in a digital file format

clip--a video segment of a larger video file

codec--an abbreviation for compressor/decompressor--software or hardware used to compress/decompress digital media.  It is a coding method that facilitates the distribution and smooth playback of digital video.  The viewer must have the same codec installed on the computer.  It is usually included with software such as Windows Media Player.  Others are available for download.

collection--a file where clips are stored

color temperatures (in degrees Kelvin ... oK):

Light Source Approx. Color Temperature
Natural Light Degrees Kelvin
Clear skylight, no clouds 12,000-20,000o K
Summer sun, blue sky 6,500o K
Daytime sunlight 5,800o K
Morning 4,200o K
Bright moonlight 3,200o K
Sunrise 2,000o K
   
Artificial Light Degrees Kelvin
Fluorescent bulbs
    Daylight
    Cool white
    Natural white
    Warm white
x
6,300o K
4,200o K
3,600o K
3,000o K
Incandescent (100-watt bulb) 2,870o K
Candlelight 1,900o K

compositing--using more than one layer of video to make a single image, such as when a TV weatherperson stands in front of a map.  In actuality, the person is probably standing in front of a solid-color (blue or green) blank wall.

compression--reducing some of the digital data in a video frame by discarding information the eye cannot see. Compressed formats include:  JPEG, MPEG, etc. 

continuity--(1) visual:  the logical succession of recorded or edited events.  For example, props must be in the same place in every shot.  (2) directional:  consistency in camera-subject relationships to avoid confusing the viewer.  For example, a train should approach from the same side of the screen each time, rather than from the left the first time and from the right subsequently.

contrast--differences between an image's brightest and darkest areas.

cookie--a pattern placed in front of a light.  It may be a cityscape, jail bars, or anything to add interest and/or realism to an otherwise boring background.

cross-fade--the procedure whereby one video clip fades out as another smoothly fades in.  The film industry refers to this as a dissolve.

cut--ending one shot and going immediately to the next with no transition.

defragment--it is not a bad idea to defrag your computer before beginning a video project to ensure optimal performance.  Defragmenting removes unnecessary spaces between bits of information so the disk operates more efficiently.  To defragment, go to:  All Programs / Accessories / System Tools / Disk Defragmenter.

depth of field--the measurement of the area in front of and behind the subject that is in focus, determined by the camera aperture setting ... typically, the subject in foreground is in focus while the background is out of focus.

digital 8--see Digital Video Formats.

digital video formats--(1) MiniDVThe majority of current digital camcorders use MiniDV cassettes that record DV-format video. Though shaped much like a traditional VHS video tape, MiniDV tapes are much smaller, measuring just 2 x 2.75 inches. MiniDV camcorders' current dominance of the market means that this format will be the industry standard for the foreseeable future.  (2) Micro MVSome Sony camcorders use Micro MV tapes, which are smaller than MiniDV tapes and record video in MPEG-2 format instead of the more common DV format. The advantage of Micro MV tapes is their size: smaller tapes allow for smaller camcorders, and models that use Micro MV cassettes are the smallest and most portable of all.  Micro MV tapes are more expensive than MiniDV cassettes, however.  (3) Mini DVD-R and DVD-RAMA small number of camcorders use 3-inch Mini DVD-R and DVD-RAM discs instead of digital videotape. While the prospect of being able to record video and then play it directly from a DVD player is appealing, this format has a number of drawbacks. DVD-R discs must be specially formatted by the camcorder before they can be played back on a home player, after which they are locked and no more information can be stored on them. (4) Digital 8:  Digital8 camcorders record digital video onto analog (non-digital) 8mm videotapes, giving users all the advantages of digital video while still using inexpensive analog tapes. These camcorders are bulkier than DV camcorders, however, and likely to grow less popular as consumers continue to adopt the digital-only MiniDV format. Digital 8 is a good choice, however, if you want to upgrade to digital from an 8mm or a Hi8 camcorder. Features are pretty much the same as a MiniDV camcorder, with one key advantage: Digital8 can play back your old 8mm and Hi8 videos (analog).

dissolve--an image transition effect of one picture gradually disappearing as another appears.

dolly--a camera mount on wheels enabling smooth movement in any direction.

drop-frame timecode--While the NTSC frame rate is frequently rounded up to 30 frames per second in conversation, technically it is 29.97 frames per second.  The first two (of the 30) frame codes are skipped each minute, except for every tenth minute.  In B&W TV days it actually was an even 30 frames per second.  When broadcasting went to color more bandwidth was needed.  The "color" info is included in the space produced by the skipped frames, keeping both color and B&W formats compatible.

DVD (digital versatile disc)--has similar formats as CDs ... DVD-R (can be recorded only once), DVD-RW (can be recorded, erased and re-recorded).  You must be sure that you use discs that are compatible with your DVD burner:  DVD-R/RW (made by Apple, Hitachi, Panasonic, Pioneer, and a few others) or DVD+R/RW (made by Dell, HP, Sony, Yamaha, and few others), i.e., be sure to match the plus or the minus. 

effects--includes:  blur, brightness decrease, brightness increase, ease in, ease out, fade in from black, fade in from white, fade out to black, fade out to white, film age old, film age older, film age oldest, film grain, grayscale, hues (cycles entire color spectrum), mirror horizontal, mirror vertical, pixelate, posterize, rotate 90, rotate 180, rotate 270, sepia tone, slow down half, smudge stick, speed up double, threshold, watercolor

file storage--video files are very hungry.  On average, one can anticipate using about 3.6MB of space per second.  A five-minute clip will use about 1GB of space.  Then, there's also the "work" space on the hard drive that you'll need for editing.  If your project is a 10-minute video, you'll need about 2GB of disk space just for storage.  In terms of total work space, multiple by four.  So, you would need approximately 8GB of work space on your computer to edit a 10-minute video.

firehosing--panning the camera back and forth and up and down to follow motion, as if trying to squirt water on a fire ... NOT a desirable technique.

fire wire--see IEEE 1394.

frame--one of many sequential images that make up video.  Higher frame rates typically produce smoother movement in the picture.

freeze frame--a single frame of video frozen like a still photo.

gobo--something put in front of or behind the subject to establish location.  For example, one could fake a restaurant set by having the name of the restaurant painted on a piece of glass and shooting through the glass on the first shot.

Hi8--see Digital Video Formats.

IEEE 1394 or FireWire--(Institute of Electrical and Electronics Engineers) a high-speed serial bus that allows enhanced computer connectivity for a wide range of devices (capable of transfer rates up to 400MB/sec).  USB 2.0 allows transfer rates of 480 MB/sec.

jack--any female socket on hardware, such as a computer or video equipment, that can accept a plug for circuit connection.

J cut (split edit)--when the audio from the next scene starts early (not a "jump cut").

jump cut--when, in editing, a subject or object is made to magically vault to a different location on the screen.

L cut (split edit)--when the audio from the current scene continues into the next video scene.

lavaliere--a small mic inconspicuously attached to the clothing of someone speaking on camera.

lens mask--a pattern placed in front of the lens, such as "binoculars," so that the viewer sees what the character sees while looking through binoculars.

lighting (3-point lighting)--(1) key light:  the principal source of light on a subject, normally positioned slightly off center and angled to provide shadow detail.  (2) fill light:  secondary lighting used to reduce or eliminate the shadows of the key light.  The fill light is usually placed midway between the camera and the subject.  (3) back light:  illumination from behind, which creates a sense of depth.  Ideally, this three-point lighting system imitates natural outdoor lighting.

lighting (types)--(1) fluorescent:  depending upon the bulb, can give off good, soft, white light.  Some bulbs give off a green or blue hue and should be avoided.  Also, some fluorescent fixtures produce a hum that can produce audio problems.  (2) incandescent:  these are the "everyday" light bulbs and tend to give off a reddish hue on video.  They are not as consistent as halogen bulbs.  (3) halogen:  while these are incandescent lights, they burn at a much higher temperature and give off a brighter, more consistent light over their lifetimes.  Halogen bulbs work well for shooting video.

manual focus--zoom in tight on something to set the focus, then all ranges will be in focus.

micro MV--see Digital Video Formats.

mini DV--see Digital Video Formats.

mini DVD-R and DVD-RAM--see Digital Video Formats.

model release--an agreement to be signed by anyone who appears a video.  Typically, the agreement specifies the event, date, compensation provisions, if any, and the rights being waived.

moiré pattern--video "artifacts" that occur when recording an object that has many thin, parallel lines, such as when someone is wearing a striped shirt or tie ... not cool.

monopod--a simple, one-legged camera mount.

.mswmm--the file name extension used when Movie Maker projects are saved

nonlinear editing--the digital "cut and paste" method of editing that is possible on a computer, allowing scenes to appear in any order ... v. linear editing, which must be done in chronological order via dubbing from one machine to the next.

NTSC--(see broadcast formats) 

PAL--(see broadcast formats)

pan--a camera move where the camera base position remains unchanged and the camera rotates for a panoramic view of the scene.

photographing a CRT monitor/TV--one must use a shutter speed of 1/30 or slower to avoid the "black line" on the screen due to video frame speed (30 frames per second).

post production--any type of video production activity that occurs following the initial recording.

POV--Point of View, how the camera sees the shot.  (1) First Person:  shooting from one character's point of view, which gives the viewer a feeling of intimacy with the character.  Actors can talk to the camera since it is one of the characters.  (2) Second Person:  shooting from the point of view of an unseen companion; camera is placed alongside the character.  Eye contact with the camera is never made.  Gives a feeling of being "with" the character without being the character. (3) Third Person:  shooting from the point of view of a detached, unseen observer.  Eye contact with the camera is never made since the observer is invisible.  This is the most frequently-used POV; shots tend to be medium to wide.  Most projects combine all three points of view.

progressive download--faux streaming.  Rather than downloading an entire file before it plays, the software begins playing it as soon as enough information has reached the player.  Nothing special is needed.  The player software does the work.

project file--the file that contains all the information about the files that have been imported into or captured in the current "project."  Project files have the .mswmm extension.

rack focus--to change the focus during the shot, e.g., when a shot begins out of focus and becomes in focus.  It can suggest the passage of time.

RCA jack--probably the most common jack found on camcorders.  It's round and has a smooth outside barrel with a 1/8-inch hole in the center.

reflector--a device, such as a sheet of white poster board or crumpled aluminum foil, used to provide indirect lighting on a subject.

rule of thirds--relates to the concept that it is more interesting when a subject, or the primary point of interest, appears off-center.  The screen is conceptually divided into thirds both horizontally and vertically.  Wherever the imaginary lines cross is theoretically a good area for a focal point.

screen aspect ratio--specifies the aspect ratio of saved movies, i.e., the relationship of width to height, such as 16:9 (widescreen) or 4:3 (standard).

SECAM--(see broadcast formats)

shutter speed--normal camcorder shutter speed is 1/60.

SMPTE time code--(pronounced "simp-tee") developed by the Society of Motion Picture & Television Engineers (SMPTE), this is the standard digital code used to synchronize sight and sound.

special effects--effects added to video footage, such as fade-ins, fade-outs, grayscale, film aging, screen rotation, etc.

split--to divide a video (or audio) file into smaller components

split edit--see J cut and L cut.

steadicam--an elaborate body-mounted camera support that enables extremely smooth camera motion regardless of the activity of the operator.  For example, the camera operator could climb stairs and the camera would glide smoothly through the process.

storyboard--a series of cartoon-like sketches that illustrate key shots--used during the planning stages of a video shoot.  Each scene has corresponding information related to audio, etc.  Also, in video editing software, that portion of the screen where clips and their transitions, etc., can be seen.

tape protection--to prevent a digital video tape from being overwritten, flip the small mechanical switch on the back of the cassette.

S-video--a process whereby the chrominance and luminance portions of the picture are transmitted separately, thereby avoiding picture quality degradation in analog video.  It results in a vastly superior picture.  It requires an S-video cable.

telephoto lens--a camera lens that can capture closeup images from a considerable distance.

timeline--the area of the user interface that shows the timing and arrangement of files or clips that make up a project

transitions (in Movie Maker)--includes:  bars, bow tie horizontal, bow tie vertical, checkerboard across, circle, circles, diagonal box out, diagonal cross out, diagonal down right, diamond, dissolve, eye, fade, fan in, fan out, fan up, filled V down, filled V left, filled V right, filled V up, flip, heart, inset down left, inset down right, inset up left, inset up right, iris, keyhole, page curl up left, page curl up right, pixelate, rectangle, reveal down, reveal right, roll, shatter in, shatter right, shatter up left, shatter up right, shrink in, slide, slide up center, spin, split horizontal, split vertical, star 5 points, stars 5 points, sweep in, sweep out, sweep up, wheel 4 spokes, whirlwind, wipe narrow down, wipe narrow right, wipe normal down, wipe normal right, wipe wide down, wipe wide right, zigzag horizontal, zigzag vertical

trim--to hide parts of a file or clip without deleting them from the original source. Files and clips can be trimmed by adjusting the start or end trim points.  There are two possible trim points, of course:  start trim point, and end trim point.

tripod--the name of Nastassja Kinski's dog in the movie Terminal Velocity, but also, a three-legged camera mount.

video file types supported by Movie Maker--.asf, .avi, .m1v, .mp2, .mp2v, .mpe, .mpeg, .mpg, .mpv2, .wm, and .wmv

white balance--a setting on many camcorders enabling the camera to determine what "white" is in lighting conditions that may not be ideal.  To set the white balance, one must use a piece of perfectly white cardboard or something similar.

Windows media file types--depending on content and purpose, Windows Media files use a variety of file name extensions, such as: .wma, .wme, .wms, .wmv, .wmx, .wmz, or .wvx

.wma--Windows Media Audio (file type)

.wmv--Windows Media Video (file type)

XLR / Cannon plug--a three-pin plug normally found on quality microphones.  

zoom--varying the focal length of the camera, bringing the subject into and out of close-up range.  The camera itself does not move.

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