Film plane
Encyclopedia
A film plane is the area inside any image taking device with a lens and a digital sensor or film; such as a camera
. The film plane varies in distance from the lens focal point in each manufacturer. Thus each lens used has to be chosen carefully to assure that the image from the lens is focused on the the exact place where the individual frame of film
or digital sensor is positioned during exposure
, the film plane is the location in which the lens creates the focused image which must be exactly upon the light-sensitive material. It is sometimes marked on a camera body with the 'Φ' symbol where the vertical bar represents the exact location.
Movie camera
s often also have small focus hooks where the focus puller
can attach one side of a tape measure
to quickly gauge the distance to objects that he intends to bring into focus. The measurement is taken from the film plane to the subject.
Due to Petzval field curvature
, the film plane upon which a lens focuses may not be a literal plane. Cameras may bend the film stock or even plate stock
slightly to compensate, improving the area of critical focus
and sharpness. Nevertheless, the general concept of a focal plane is understood to refer to this position in the camera sensor relative to the lens.
.
Camera
A camera is a device that records and stores images. These images may be still photographs or moving images such as videos or movies. The term camera comes from the camera obscura , an early mechanism for projecting images...
. The film plane varies in distance from the lens focal point in each manufacturer. Thus each lens used has to be chosen carefully to assure that the image from the lens is focused on the the exact place where the individual frame of 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...
or digital sensor is positioned during exposure
Exposure (photography)
In photography, exposure is the total amount of light allowed to fall on the photographic medium during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value and scene luminance over a specified area.In photographic jargon, an exposure...
, the film plane is the location in which the lens creates the focused image which must be exactly upon the light-sensitive material. It is sometimes marked on a camera body with the 'Φ' symbol where the vertical bar represents the exact location.
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...
s often also have small focus hooks where the focus puller
Focus puller
A focus puller, or 1st assistant cameraman, is a member of a film crew’s camera department whose primary responsibility is to maintain image sharpness on whatever subject or action is being filmed....
can attach one side of a tape measure
Tape measure
A tape measure or measuring tape is a flexible form of ruler. It consists of a ribbon of cloth, plastic, fiber glass, or metal strip with linear-measurement markings. It is a common measuring tool. Its flexibility allows for a measure of great length to be easily carried in pocket or toolkit and...
to quickly gauge the distance to objects that he intends to bring into focus. The measurement is taken from the film plane to the subject.
Due to Petzval field curvature
Petzval field curvature
Petzval field curvature, named for Joseph Petzval, describes the optical aberration in which a flat object normal to the optical axis cannot be brought into focus on a flat image plane....
, the film plane upon which a lens focuses may not be a literal plane. Cameras may bend the film stock or even plate stock
Photographic plate
Photographic plates preceded photographic film as a means of photography. A light-sensitive emulsion of silver salts was applied to a glass plate. This form of photographic material largely faded from the consumer market in the early years of the 20th century, as more convenient and less fragile...
slightly to compensate, improving the area of critical focus
Critical focus
In a photograph, the area of critical focus is the portion of the picture that is optically in focus. This does not relate to depth of field which describes apparent sharpness....
and sharpness. Nevertheless, the general concept of a focal plane is understood to refer to this position in the camera sensor relative to the lens.
.