Film frame
Encyclopedia
In filmmaking
, video production
, animation
, and related fields, a film frame or video frame is one of the many still (or nearly so) images which compose the complete moving picture. The term is derived from the fact that, from the beginning of modern filmmaking toward the end of the 19th century, and in many places still up to the present, the single images have been recorded on a strip of photographic film
that quickly increased in length, historically; each image on such a strip looks rather like a framed picture when examined individually.
The term may also be used more generally as a noun or verb to refer to the edges of the image as seen in a camera viewfinder or projected on a screen. Thus, the camera operator can be said to keep a car in frame by panning with it as it speeds past.
When the moving picture is displayed, each frame is flashed on a screen for a short time (nowadays, usually 1/24th, 1/25th or 1/30th of a second) and then immediately replaced by the next one. Persistence of vision
blends the frames together, producing the illusion of a moving image.
The frame is also sometimes used as a unit of time, so that a momentary event might be said to last six frames; the actual duration of which depends on the frame rate
of the system, which varies according to the video or film standard in use. In North America and Japan, 30 frames per second is the broadcast standard, with 24 frame/s now common in production for high-definition video. In much of the rest of the world, 25 frame/s is standard.
In systems historically based on NTSC
standards, for reasons originally related to the color subcarrier in analog NTSC TV systems, the exact frame rate is often the nominal frame rate divided by 1.001 -- so, for example, a nominal 30fps sequence is actually shot at 30/1.001 = 29.97002997... fps. This leads to many synchronization problems which are unknown outside the NTSC world, and also brings about hacks such as drop-frame timecode.
In film projection, 24 frame/s is the norm, except in some special venue systems, such as IMAX
, Showscan
and Iwerks 70, where 30, 48 or even 60 frame/s have been used. Silent films and 8 mm
amateur movies used 16 or 18 frame/s.
s. Normally, 24 frames are needed for one second
of film. In ordinary filming, the frames are photographed automatically, one after the other, in a movie camera
. In special effects or animation
filming, the frames are often shot one at a time.
The size of a film frame varies, depending on the still film format
or the motion picture film format. In the smallest 8 mm
amateur format for motion pictures film, it is only about 4.8 by 3.5 mm, while an IMAX
frame is as large as 69.6 by 48.5 mm. The larger the frame size is in relation to the size of the projection screen
, the sharper the image will appear.
The size of the film frame of motion picture film also depends on the location of the holes, the size of the holes, the shape of the holes. and the location and type of sound stripe.
The most common film format, 35 mm, has a frame size of roughly 22 by 16 mm when used in a still 35 mm camera where the film moves horizontal but the frame size varies when used for motion picture where the film moves vertically (with the exception of VistaVision where the film moves horizontally). Using a 4-perf pulldown, there are exactly 16 frames in one foot of 35 mm film, leading to film frames sometimes being counted in terms of "feet and frames". A system called KeyKode
is sometimes used to identify specific physical film frames in a production.
across the screen. Analog blanking intervals separated video frames in the same way that frame lines did in film. For historical reasons, most systems used an interlaced scan system in which the frame typically consisted of two video fields sampled over two slightly different periods of time. This meant that a single video frame was usually not a good still picture of the scene, unless the scene being shot was completely still.
With the dominance of digital technology, modern video systems now represent the video frame as a rectangular raster
of pixel
s, either in an RGB color space or a color space such as YCbCr, and the analog waveform is typically found nowhere other than in legacy I/O devices.
Standards for the digital video frame raster include Rec. 601 for standard-definition television
and Rec. 709
for high-definition television
.
Video frames are typically identified using SMPTE time code
.
aspect of the film frame itself, with some animation showing characters leaving what is assumed to be the edge of the film or the film malfunctioning. This latter one is used often in films as well.
This hearkens back to some early cartoons, where characters were aware of the fact they were in a cartoon, specifically the fact they could look at the credits and be aware of something that isn't part of the story as presented. These jokes include -
Filmmaking
Filmmaking is the process of making a film, from an initial story, idea, or commission, through scriptwriting, casting, shooting, directing, editing, and screening the finished product before an audience that may result in a theatrical release or television program...
, video production
Video production
Video production is videography, the process of capturing moving images on electronic media even streaming media. The term includes methods of production and post-production...
, animation
Animation
Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
, and related fields, a film frame or video frame is one of the many still (or nearly so) images which compose the complete moving picture. The term is derived from the fact that, from the beginning of modern filmmaking toward the end of the 19th century, and in many places still up to the present, the single images have been recorded on a strip of photographic film
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...
that quickly increased in length, historically; each image on such a strip looks rather like a framed picture when examined individually.
The term may also be used more generally as a noun or verb to refer to the edges of the image as seen in a camera viewfinder or projected on a screen. Thus, the camera operator can be said to keep a car in frame by panning with it as it speeds past.
When the moving picture is displayed, each frame is flashed on a screen for a short time (nowadays, usually 1/24th, 1/25th or 1/30th of a second) and then immediately replaced by the next one. Persistence of vision
Persistence of vision
Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina....
blends the frames together, producing the illusion of a moving image.
The frame is also sometimes used as a unit of time, so that a momentary event might be said to last six frames; the actual duration of which depends on the frame rate
Frame rate
Frame rate is the frequency at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems...
of the system, which varies according to the video or film standard in use. In North America and Japan, 30 frames per second is the broadcast standard, with 24 frame/s now common in production for high-definition video. In much of the rest of the world, 25 frame/s is standard.
In systems historically based on NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
standards, for reasons originally related to the color subcarrier in analog NTSC TV systems, the exact frame rate is often the nominal frame rate divided by 1.001 -- so, for example, a nominal 30fps sequence is actually shot at 30/1.001 = 29.97002997... fps. This leads to many synchronization problems which are unknown outside the NTSC world, and also brings about hacks such as drop-frame timecode.
In film projection, 24 frame/s is the norm, except in some special venue systems, such as IMAX
IMAX
IMAX is a motion picture film format and a set of proprietary cinema projection standards created by the Canadian company IMAX Corporation. IMAX has the capacity to record and display images of far greater size and resolution than conventional film systems...
, Showscan
Showscan
Showscan is a cinematic process developed by Douglas Trumbull. Similar to 70 mm wide-screen processes, it uses 65 mm film, but photographs and projects it at 60 frames per second – 2.5 times faster than standard movie film...
and Iwerks 70, where 30, 48 or even 60 frame/s have been used. Silent films and 8 mm
8 mm film
8 mm film is a motion picture film format in which the filmstrip is eight millimeters wide. It exists in two main versions: the original standard 8mm film, also known as regular 8 mm or Double 8 mm, and Super 8...
amateur movies used 16 or 18 frame/s.
Physical film frames
In a strip of movie film, individual frames are separated by frame lineFrame line
A frame line is the unused space that separates two adjacent images, or film frames, on the release print of a motion picture. They can vary in width; a 35 mm film with a 1.85:1 hard matte has a frame line approximately 8 millimeters high, whereas both a full frame negative and the anamorphic...
s. Normally, 24 frames are needed for one second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
of film. In ordinary filming, the frames are photographed automatically, one after the other, in a movie camera
Movie camera
The movie camera is a type of photographic camera which takes a rapid sequence of photographs on strips of film which was very popular for private use in the last century until its successor, the video camera, replaced it...
. In special effects or animation
Animation
Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
filming, the frames are often shot one at a time.
The size of a film frame varies, depending on the still film format
Film format
A film format is a technical definition of a set of standard characteristics regarding image capture on photographic film, for either stills or movies. It can also apply to projected film, either slides or movies. The primary characteristic of a film format is its size and shape.In the case of...
or the motion picture film format. In the smallest 8 mm
8 mm film
8 mm film is a motion picture film format in which the filmstrip is eight millimeters wide. It exists in two main versions: the original standard 8mm film, also known as regular 8 mm or Double 8 mm, and Super 8...
amateur format for motion pictures film, it is only about 4.8 by 3.5 mm, while an IMAX
IMAX
IMAX is a motion picture film format and a set of proprietary cinema projection standards created by the Canadian company IMAX Corporation. IMAX has the capacity to record and display images of far greater size and resolution than conventional film systems...
frame is as large as 69.6 by 48.5 mm. The larger the frame size is in relation to the size of the projection screen
Projection screen
A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. Projection screens may be permanently installed, as in a movie theater; painted on the wall; or semi-permanent or mobile, as in a conference room...
, the sharper the image will appear.
The size of the film frame of motion picture film also depends on the location of the holes, the size of the holes, the shape of the holes. and the location and type of sound stripe.
The most common film format, 35 mm, has a frame size of roughly 22 by 16 mm when used in a still 35 mm camera where the film moves horizontal but the frame size varies when used for motion picture where the film moves vertically (with the exception of VistaVision where the film moves horizontally). Using a 4-perf pulldown, there are exactly 16 frames in one foot of 35 mm film, leading to film frames sometimes being counted in terms of "feet and frames". A system called KeyKode
Keykode
KeyKode is an Eastman Kodak Company advancement on edge numbers, which are letters, numbers and symbols placed at regular intervals along the edge of 35 mm and 16 mm film to allow for frame-by-frame specific identification...
is sometimes used to identify specific physical film frames in a production.
Video frames
Historically, video frames were represented as analog waveforms in which varying voltages represented the intensity of light in an analog raster scanRaster scan
A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems...
across the screen. Analog blanking intervals separated video frames in the same way that frame lines did in film. For historical reasons, most systems used an interlaced scan system in which the frame typically consisted of two video fields sampled over two slightly different periods of time. This meant that a single video frame was usually not a good still picture of the scene, unless the scene being shot was completely still.
With the dominance of digital technology, modern video systems now represent the video frame as a rectangular raster
Raster
Raster may refer to:* Raster graphics, graphical techniques using arrays of pixel values* Raster graphics editor, a computer program* Raster scan, the pattern of image readout, transmission, storage, and reconstruction in television and computer images...
of pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s, either in an RGB color space or a color space such as YCbCr, and the analog waveform is typically found nowhere other than in legacy I/O devices.
Standards for the digital video frame raster include Rec. 601 for standard-definition television
Standard-definition television
Sorete-definition television is a television system that uses a resolution that is not considered to be either enhanced-definition television or high-definition television . The term is usually used in reference to digital television, in particular when broadcasting at the same resolution as...
and Rec. 709
Rec. 709
ITU-R Recommendation BT.709, more commonly known by the abbreviations Rec. 709 or BT.709, standardizes the format of high-definition television, having 16:9 aspect ratio. The first edition of the standard was approved in 1990....
for high-definition television
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...
.
Video frames are typically identified using SMPTE time code
SMPTE time code
SMPTE timecode is a set of cooperating standards to label individual frames of video or film with a time code defined by the Society of Motion Picture and Television Engineers in the SMPTE 12M specification...
.
Digital film frames
Technologically, digital film systems use a hybrid between the traditional video and film technologies, and use digital technologies throughout, without reference to legacy video standards. In general, the traditional terminology of film production is still used in modern digital cinematography in preference to video terminology, even though no physical film is used in the entire production process.Showing film frames in animation and movies
Some humor in animation is based on the fourth wallFourth wall
The fourth wall is the imaginary "wall" at the front of the stage in a traditional three-walled box set in a proscenium theatre, through which the audience sees the action in the world of the play...
aspect of the film frame itself, with some animation showing characters leaving what is assumed to be the edge of the film or the film malfunctioning. This latter one is used often in films as well.
This hearkens back to some early cartoons, where characters were aware of the fact they were in a cartoon, specifically the fact they could look at the credits and be aware of something that isn't part of the story as presented. These jokes include -
- Split frames - Where the fourth wall is broken by two frames, the lower half of the previous frame and the upper part of the next frame, showing at once, with jokes involving them including a character crossing the frame itself.
- Film Break - A famous form of joke, where the film either snaps or is deliberately broken, with often the fourth wall coming into play during this period when, rightfully, there should be nothing on screen.
- Exiting the frame - This joke, an extension of the split frames joke, has characters depart from the sides of the frame, sometimes finding themselves falling out of the cartoon entirely.
See also
- Aspect ratio (image)Aspect ratio (image)The aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this...
- Frame rateFrame rateFrame rate is the frequency at which an imaging device produces unique consecutive images called frames. The term applies equally well to computer graphics, video cameras, film cameras, and motion capture systems...
- List of film formats
- Motion blindness
- WidescreenWidescreenWidescreen images are a variety of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film....
- Shot (film)Shot (film)In film, a shot is a continuous strip of motion picture film, created of a series of frames, that runs for an uninterrupted period of time. Shots are generally filmed with a single camera and can be of any duration. A shot in production, defined by the beginning and end of a capturing process, is...