MICROFILM GLOSSARY
Acetate Film - Safety film with a base composed principally of cellulose acetate or triacetate.
ANSI - American National Standards Institute
ANSI clip – a clip that holds a reel of microfilm to allow labeling without
a box
Aperture Card - A card which holds microfilm intended to protect the film and facilitate loading by a scanner or viewer. (2)a standard Hollerith encoded IBM-style punch card or tab size card with a rectangular hole cut into it which is designed to hold a
frame of 35mm transparency. Typically, aperture cards are used to store blueprints and engineering drawings.
Archival Quality
- The degree to which a processed print or film will retain its characteristics during a period of use and storage; the ability to
resist deterioration for a lengthy specified time.
Archival Value – the determination that records possess value in documenting
the history of an organization and are worthy of permanent preservation.
Base - The transparent plastic on which the photographic
emulsion is coated.
Camera, Planetary – a type of microfilm camera in which the film and document remain stationary during filming
and the lighting is from an overhead source. The document is on a plane surface at time of filming. Sometime referred to as
an over-head (lighted) or flatbed camera. 16mm planetary cameras can accommodate documents up to 14x17 inches and have a degree
of auto adjustment for colors. They are used to film miscellaneous size, colored documents and small bound books. 35 mm planetary cameras can accommodate 24x36 inch documents are used to film large oversized documents including maps, large journals
and bound books. Planetary cameras provide the highest resolution images but compromise productivity due to individual handling
of each document. Planetary reduction ratios range from 21X-32X. An experienced operator can sustain filming rates up to 500
letter-size documents per hour. However, large pages, fragile documents or bound volumes can take several minutes each to position,
expose and remove. Some planetary cameras feature automatic page feeders to enhance productivity which transport documents to
the exposure surface where they are stopped momentarily for microfilming. Other Planetary camera’s offer continuous form feed
attachments that pull the forms through one page at a time via sprocket gears that fit through the holes on the side of the green
bar sheets and operate in a similar fashion as the automatic page feeders.
Camera, Rotoline – a type of rotary microfilm camera designed to photograph continuous forms. The leading
edge of the stack of fanfold forms is set on the shelf and the first page is inserted into the mouth of the camera. The forms re-stack
fan folded in the document hopper at the bottom of the camera. Some planetary camera’s offer continuous form feed attachments
that pull the forms through one page at a time via sprocket gears that fit through the holes on the side of the green bar sheets. Rotoline camera’s have lower resolution than rotary or planetary cameras.
Camera, Step and Repeat – a type of microfilm camera which
can expose a series of separate images on an area of 105mm film according to a pre-determined format, usually in orderly rows and
columns. They are primarily used to create source document fiche. Depending on the model, a step and repeat camera can accept
105mm film in 50 or 100 ft rolls with individual fiche being cut to size following exposure or development or alternatively precut
105mmx148mm or 4x6in sheets. Step and repeat cameras typically offer 24-48x reduction ratios. Step and repeat cameras
resemble planetary cameras in design and operation from the operator’s perspective but the camera automatically steps over to the
next image position on the film between exposures making the filming rate considerably lower than planetary cameras. A fully
trained operator can expect to maintain only 300 images per hour. These camera’s also record one or more lines of eye-legible
title information in the microfiche heading area. Newer models incorporate character-generators and computer controllers for
the purpose.
Camera, Aperture Card – a type of microfilm camera designed to film engineering drawings or other large source documents
onto unexposed 35mm microfilm frames which are pre-mounted into tabulating-size cards. These cameras were developed as a more
convenient alternative to manual cutting and mounting of individual frames of from developed rolls of 35mm microfilm. Aperture
card cameras are planetary in operation, design and resolution. These cameras typically offer 18-29x reduction ratios. Aperture card cameras are actually camera/processors. Following exposure, camera cards pass through a processing chamber and
are delivered, fully developed in about a minute. These cameras are used primarily by county clerks to film their daily recordings,
abstract pages and plats. When filming letter of legal size documents up to 4 pages can be filmed in one frame. These
cameras were used primarily by end users with no production time limits.
Cartridge – An enclosed container that facilitates loading
and unloading a reel of microfilm with minimal handling.
Carousel – a filing system that rotates horizontally like a lazy Susan and
may house roll film boxes, roll film in ANSI clips or film cartridges
Cine Mode – a manner of positioning an image on microfilm when
the data line runs the width of the film with the image oriented along the length of the film i.e. like cinematic film. Also
referred to as portrait mode
Comic mode – a manner of positioning the image on microfilm when the data lines run the length of the
film i.e. like a comic strip. Also referred to as landscape mode
Computer Output Microfilm (COM) - Microfilm containing data
produced by a recorder from computer-generated electrical signals. A computer output microfilmer is a recorder that coverts data from
a computer into human-readable language and records it on microfilm. A process of converting the data on a magnetic computer tape
directly onto microfilm by means of a cathode ray tube, electron beam, or other electronic process.
Computer Output Microfilm (COM)
Recorders – a devise that produces computer-output microfilm by combining the functionality of a computer printer and microfilm camera. Like a microfilm camera, a COM recorder produces page images that require magnification for viewing or printing. COM-generated
microimages may contain text or graphics. The information may be records onto microfiche, roll microfilm or aperture cards. COM production begins with computer-processible information that would otherwise be printed onto paper. The properly formatted
information is transferred either manually or electronically to a COM recorder, which created microimages which resemble miniature
versions of a printed page. COM recorders can operate online or offline. Typically, in an online application, the host
computer recognized the COM recorder as a type of printer. Offline COM recorders are standalone devices connected to a separate
computer which records the information onto a magnetic tape which must be physically transported from the computer to the COM recorder. Many offline COM recorders are operated by service bureaus.
Contact printing, microfilm – a process of film image duplication requiring
the emulsion of the original film to be placed in contact with the emulsion of the copy film while exposing to a light source followed
by development.
Continuous forms – a group of forms consisting of strips of connection forma that can be separated by perforation.
Also knows as fanfold or green bar computer paper.
Densitometer - A device used to measure the optical transmittance or reflectance
density of an image or base by measuring the amount of incident light reflected or transmitted.
Density - The measure of the
degree of contrast between an image such as a microform image, and its background.
Developer - A chemical reagent used to produce
a visible image on an exposed photographic layer. It may take many forms for different materials, such as conventional formulas for
silver emulsions; plain water used to develop blueprints; or a gas, such as ammonia vapor, used to develop diazo films and prints.
Diazo Film - A slow print film, sensitized by means of diazonium salts, which, after exposure to light strong in the blue to
ultraviolet spectrum and after development, forms an image. Diazo film generally produces nonreversible images, i.e., a positive image
will produce a positive image and a negative image will produce a negative image.
Dry Silver Film - A nongeletin silver film
that is developed by application of heat.
Emulsion - A single or multilayered coating of gelatinous material on a transparent base carrying
radiant energy reactive chemicals that create a latent image upon exposure. Processing techniques produce a final, visible, usable
image.
Exposure - The act of subjecting sensitized materials to radiant energy.
Film - Any sheet or strip of transparent plastic coated with a light-sensitive emulsion.
Filmer/Scanners - These are microfilm cameras that can also operate as electronic document scanners. A Filmer/scanner
produces a microfilm image and a digital image of a page in a single exposure and are intended for applications where both microform
and electronic copies are desired. These units offer a labor-saving alternative to microfilming and scanning source documents
in separate operations with different equipment. Alternatively, a Filmer/scanner can be used as a microfilm camera only or as
a document scanner only for applications that do not require both types of images. A Filmer/scanner may be rotary or planetary
in design and operation. Rotary Filmer/scanners, the most common configuration, produce 16mm microfilm, like their camera-only
counter parts.
Fixer - A solution used to remove undeveloped silver halides from photosensitized emulsions. The fixer usually
contains sodium or ammonium thiosulfate (hypo), a hardening agent and an acid or acid salt.
Frame - That area of the film exposed
to light in a camera during one exposure, regardless of whether or not the area is filled by the document
Generation – a measure
of the remoteness of a particular copy from the original material. The picture taken of a document by a camera is termed first
generation microfilm (camera microfilm). Copies made from this fires generation are second generation etc.
Halide - Any compound
of chlorine, iodine, bropane or fluorine and another element. Solver bromide, silver chloride and silver iodine are the light-sensitive
materials in most silver emulsions.
Hardcopy - A reproduction of a document usually enlarged and on paper.
Hybrids – seeFilmer/scanner and scanner/Filmer
Image - A unit of information.
Image count – a method of retrieval of a microfilm image
that optically counts the images on a roll of microfilm using and external computer index to determine the image number
Imaging - To
copy or capture a record that can be used to generate an intelligible reproduction of that record. May include the use of microforms
or digital images.
Indexing - Alphabetic or numeric list of items that serve as a measure or indicator of something. Determining the
name by which a document is to be filed or referenced. (2) The means of assigning an identity to electronic documents or files, enabling
them to be retrieved from within the electronic archive. (3) A systematic guide that allows access to specific items contained within
a larger body of information.
Inspection – a process of verifying the organization and quality of images on microfilm
Master – a copy
of a document, or in some processes, the original itself from which copies can be made
Microfiche - Microform containing multiple
microimages in a grid pattern on a transparent sheet of film. (2) Microfiche is a microform, usually 105mm x 148mm or 4x6 inches,
containing a number of individual photographic images, generally representing a single file or record. Jacket Microfiche usually hold
five strips of 16mm roll film in a transparent plastic wallet in a 12 x 5 frame matrix. Combination fiche have a pocket for up to
three 35mm frames plus up to thirty-six 16mm frames. Step-and-Repeat Fiche are sheets of silver halide film with up to 96 document
images filmed directly onto the film sub-strate.
Microfilm - A fine-grain film containing an image greatly reduced in size from the
original or the raw film to be used for microphotographs. (2) The process of recording microphotographs on film. Microform containing
multiple microimages on a roll of transparent film. (3) Microfilm is 16mm or 35mm silver halide photographic file on 100 or
215 foot reels used to record documents and drawings respectively. 16mm 100 ft film holds around 2,500 document images filmed at 24
– 32x reduction: 35mm 100 ft film can record around 650 images at reductions from 18 - 21x (depending on the size of the originals).
Microfilm
Camera – a camera that produces highly miniaturized reproductions of paper documents.
Microfilm Duplicator – a devise that produces
copies of microforms
Microfilm jacket – a transparent carrier with sleeves or channels for insertion of single or multiple strips of
16mm or 35mm microfilm
Microfilm processor – a devise that develops microfilm images following exposure.
Microform - A generic term for
any form containing micro-images. Microfiche and microfilm are examples of types of microforms.
Microform scanner – a device
that produces electronic images from micro-images
Microfilm Service Bureau – a business that performs one or more micrographic services
to customer specification using the customer own documents, computer data or other source material
Micrographics - The art of producing
or reproducing information in miniature form.
Mil Spec - Filming to government filming standards.
Mode – a manner of positioning
images
Mounter – a devise for simultaneously cutting, positioning and fastening film frames in aperture cards.
Negative
image - A photographic image with light lines, characters and neutral tones on a dark background.
PH - A measure of the acidity
of alkalinity of chemical substances, expressed as
The logarithm of the reciprocal of the hydrogen ion concentration.
Polarity, microfilm
– the characteristic in a film image that is either “positive” or “negative”, that is sign reversing. A negative image is the opposite
of the original and positive is the same as the original.
Positive / Negative Film - Positive microfilm has tonal values which are
the same as the original; light areas are recorded as light, and dark areas are recorded as dark. Negative microfilm, as you'd expect,
is the opposite; light areas are recorded as dark and dark areas are recorded as light. Scanning from negative microfilm can reduce
the appearance of flaws in the microfilm images.
Processing – the various procedure and chemicals required to develop the latent image
on the emulsion of microfilm. Also known as film developing
Quality index (QI) - A system identifying particular degrees
of resolution taking into account both the size of the typeface in the original (usually the lower case 'c') and the quality of resolution
achieved in the microfilm.
Reader/printer – a device that magnifies micro-images for viewing or printing. A micro-image projection
device which optically enlarges and displays the image on a screen and which also prints a copy of that image on paper using office
copier technology
Reduction - A reproduction smaller than the master, expressed as the number of times a given linear dimension of
an object is reduced, e.g., 16x.
Reduction Ratio - The ratio between the size of the original document and the size at which it appears
on your roll film. For example, an 8.5" x 11" document filmed at a 25x reduction ratio will appear as a .34" x .44" frame on the microfilm.
It is helpful for the scanner operator to know the reduction ratio of the documents on the roll film as it makes setup time much faster.
Resolution - The ability of optical systems and photographic materials to render visible fine detail of an object; a measure of sharpness
of an image, expressed as the number of lines per millimeter, discernible in an image. Resolution is measured by examining a microfilmed
resolution test chart under a microscope to determine the smallest pattern in which lines cam be distinguished both horizontally and
vertically. The measure of sharpness of an image, such as a microform image.
Scanner/filmers - Most scanner/filmers are high speed,
heavy duty devised intended for large-scale images projects, centralized document conversion departments or commercial service bureaus. The most prevalent use of scanner/filmers are in the proof department of banks and government agencies where the speed of retrieval
of digital images meets their constituents needs and the microfilm meets the long term requirements of their State Archives.
Silver
film - Film that is coated with a silver-halide emulsion.
Silver Halide - A compound of silver and one of the following elements
known as halogens- chlorine, bromine, iodine, fluorine. See Silver Film.
Source document microfilming – the production of microforms
from paper documents
Spool - The device used to wind up film in a camera or processor after it has been exposed; also called a receiving
or take-up spool.
Step Test - A series of orderly varied exposures made to determine the optimum exposure of either film or
paper prints. 2) To test for contract for latitude, a step tablet is used in a single exposure.
Targets and certifications – sheets
of paper which are microfilmed together with documents to serve as index points or to make the certification a part of the micro-images
Unitized
media – microfiche, microfilm, jackets, aperture card and other flat microforms are unitized so each file is recorded on a separate
microform. If space remains within a given fiche, it is left blank. A microfilm jacket is updateable.
Vesicular Film - Film,
whose light-sensitive element is suspended in a plastic layer and which, on exposure, creates strains within the layer to form a latent
image. The strains are released and the latent image made visual by heating the plastic layer. The image becomes permanent when the
layer cools.