In information entities, it is necessary to have a place that has the minimum conditions to provide a service capable of offering users the possibility of adequately consulting the desired information.
The growth of information sources means that more efficient methods for locating it are sought every day; Due to this, the funds and the intense use of the documents that comprise it, have seen the need to look for ways that help to save more space, to find the original materials more quickly, to preserve the specimens. unique and those documents that are badly damaged.
The technique of filming in microcarriers has contributed to these issues, due to the fact that the material is durable, easy to handle, among other issues that will be revealed in the course of the work.
It is, the microfiche, one of the information supports used in information institutions, although with the advancement and technological development that we are experiencing in our days it has been left a little behind in time.
Among the microcarriers we can mention as the best known: the microfilm, the opening tabs, the jacket tabs, the microfiche, etc., the latter being the main object of our work.
II. Microfiche
The main reprographic procedure for archives in developing countries in the 1990s was micrography, a technique associated with the production, handling, and use of microforms and some rapid copying apparatus to obtain paper copies directly from the original.
Among the forms that microcarriers take, the microfiche plays a special role.
It is argued that during those years, those who adopted micrography as a means of preservation could feel confident that their printed materials were well preserved and had the vital technology to transfer the material to other media if desired.
Due to its low cost and high quality, the micrograph, although it faces difficulties, was very well accepted by institutions of different kinds in order to preserve printed materials.
The microfiches are included within the microforms, the latter according to the General Information and UNISIST program "cover all kinds of microimages, these can be transparent or opaque, in the form of film reels, frames (a single image) or sheets or cards of various sizes.
They are reduced photographic images of documents that must be enlarged in a device or projector to be able to read them ”.
Of the microfiches it can be said that they are rectangular, transparent and flat microforms which contain the number of micro-images placed in columns and rows, can have a title (…) their support is a plastic polyester film and the binder is a gelatin layer.
The microfiche is a flat film of 105 x 148 mm as standard, it can be 72; 98 or 270 frames, this measurement is given by the lens used.
The microfilming technique is the process by which negative copies of a reduction coefficient of 10 to 100 times are obtained from documents. This technique predates that of the microfiche.
It is possible to use, for the storage of information and / or the exchange, microfiche of 98 squares.
In the German Democratic Republic (GDR) there is the Pentaka line where a complete system for making microfiche is offered. Among which we can mention:
Pentaka A 100 camera
Allows the microfiche copy of originals of format A 4 to A 2. Performs the functions automatically. Copy in single or double squares, as needed. It has reduction factors between 20 and 27.5. 30 to 40 microfiche can be made per day.
Pentaka A 200 Camera
For copying plans of format up to A 0. Developing equipment E 100. Performs development, fixing, washing and drying of the cards. Process 44 chips per hour.
Pentaka K100
Make positive copies (silver film) by contacting the negative microfiche. Make 200 copies / hour.
Diazo DD 1 Duplicator
Composed of a DDB 1 exposure unit and a DDE 1 development unit. Duplication is carried out by contacting the silver film with the diazo exposed to the light intensity of a mercury lamp and developed with 25% ammonia vapors.
Pentaka R 100 printed reader
Copy of positive film to sensitized paper in A 4 format. SET desitometer. For making film density measurements. Make indications between 0 and 2.5.
FUJI Microfiche Processor Chamber
This system is based on the same principles as the Pentaka system. The processing chamber is a whole unit, since it automatically performs all the processes: copy, develop, fix, wash and dry the film.
Both the Pentaka and FUJI systems are standardized for 105 x 148 mm and 60 frame microfiche (with titles).
II. 1. Advantages of microfiche systems
- This system fulfills its objectives and functions according to the use made of it. As for the times of access to information, microfiche allows to locate it more quickly, since the search through cards is faster than through scrolls. Regarding the handling of the film, the microfiche system is more comfortable. The microfiche allows a saving of space that can decrease up to 95%. As a storage medium it is durable and inexpensive. It allows material savings, since a large number of copies of one or more publications copied on film can be made available with considerable paper savings. The microfiche reduces the physical work of the personnel. It has application in all branches of science and economics.With the microfiche there is the possibility of applying automation in the search for information. The standards for creating, processing, storing, and reading have not been made absolute (all that is needed is light and magnification). Copies are recognized as legally acceptable substitutes for original documents • This technique can theoretically store high quality gray scale images economically.
II. 2. Disadvantages of microfiche systems
- The film can be scratched with handling. It should generally be stored in a vault and copies distributed for general use only. Each generation or copy that is made loses resolution (10%). The majority of printers and readers must handle the film and the automatic copies made by the printer, reader, which are of very low quality. Film making variations can only be determined after filming has been completed and bad pages should be re-filmed and placed in their proper place.
II. 3. Standards for the preparation of microfiche
For the preparation of microfiche, international standards must be taken into account.
These standards include how microfiche should be made; the distribution of the tables, how to distribute the heading of the microfiche, etc.
Adequate technical attention is essential to maintain high-tech equipment.
The premises for the equipment of a system, either Pentaka or FUJI or any other, must be provided according to the manufacturer's instructions (stability of the floor, premises lights, water consumption, electricity, temperature and humidity of the premises).
The scheduled maintenance of the equipment is essential and greatly prolongs the life of the equipment.
The qualification and knowledge that the personnel have in handling the equipment are of great importance.
III. Conservation of microfiche
To preserve silver halide films, the following factors must be taken into account:
- Good washing for the elimination of sodium thiosulfate and that they resist longer without fear of deterioration. Handle them with extreme cleanliness, touching it only with non-fibrous gloves and avoiding scratches. Air-conditioned premises. Careful work in the preparation of the microfiche would be useless if we do not guarantee adequate premises and their air conditioning. The temperature and humidity of the air are one of the factors that most influence the deterioration of films. If the storage conditions are poor, the photographic characteristics undergo changes. For example: at high humidity, the formation of fungi and bacteria is favored. Virgin photographic material must be kept in refrigerators or rooms with a temperature below 18 ° C and humidity between 50 and 60%.¨ Films already exposed must be kept in places protected from the action of the sun, air-conditioned between 16 and 18 ° C and 50 and 60% relative humidity, always trying to keep these parameters within these ranges, since sudden variations in temperature or Moisture could cause damage to the film.¨ Quality checks should be carried out over various periods of time on a random group of films to see how they are preserved.to see how they are preserved.to see how they are preserved.
IV. Material characteristics
This was extracted from the recommendations related to computer generated microfiche (com.) Based on the Manual of Information and Documentation on Industrial Property taking into account the draft international standard ISO / DIS 5126.
Thickness
The thickness of the microfiche must provide it with sufficient rigidity to allow easy handling. The range of gross thicknesses of the microfiche excluding, if necessary, the anti-halo layer of the heading must be:
For cellulose acetate films: 0.13mm to 0.23mm for polyester based films: 0.10mm to 0.23mm.
An opaque or translucent anti-halo layer of the heading is optional (the use of this anti-halo layer restricts the possibilities of reproduction). If an anti-fog layer is used in the header, the thickness of the microfiche should not increase more than 0.01 mm.
Identification of the sensitive layer
To make it easier to copy one microfiche to another, a notch or cut in one corner can be used to identify the sensitive layer of the microfiche. The notch should be made on the smallest side of the microfiche, near the appropriate corner and can be any shape, but its depth should not be more than 1.6 mm.
When a corner cut is used it will only be made at the appropriate corner of the heading. The nominal dimensions of the cut should be: 6 mm in the length of the microfiche and 9 mm in its width.
The sensitive layer must be identified by one of the following methods:
- Method A - When the virgin film or the microfiche is placed horizontally with respect to its greater side and the notch in the lower right corner or the cut in the upper left corner, the sensitive layer is in front of the observer. Method B - When the virgin film or microfiche is placed vertically and the notch or cut in the upper right corner, the sensitive layer is in front of the observer.
à Rounding of the corners and measures relative to the cut
corners The corners of the microfiche can be rounded, except the one that has been cut. When rounding the corners, no more than 3 mm should be removed from the two sides that make up the corner. When fragments have been removed from an edge by rounding or cutting a corner, the straight line extending the edge in the desired direction should serve as the basis for measurement of dimensions and spacing.
Header
The heading above the block of images on each tab should be reserved for identification references. All characters in the heading must be vertical and in the sense of reading. All elements must be readable without the need for enlargement.
The minimum areas reserved for the heading.
If an additional space is required for the heading, the area assigned to the entire row (s) of images below should be used.
The heading occupies the top of the microfiche. The minimum area reserved for the heading should be used only for this purpose and for identification purposes, and not for micro-images.
Pagination
When the microfiche is positioned so that the heading is vertical and in the direction of reading, the first microimage should be located in the upper left corner of the hatched area.
The frames of the following images should appear side by side, from top to bottom, from column to column and from left to right (vertical pagination), or side by side from left to right, from row to row and top to bottom (horizontal pagination).
Microfiche Identification-continued
When continuation microfiches are used, each microfiche in the series, including the first one, must be identified sequentially by an order number. The last microfiche in the series, as long as possible, should be identified as such.
Frame identification
When coordinates are used to identify the location of the images, letters should be used to identify the rows. Starting with the top row below the heading, the 1st row will be A, the 2nd row will be B, etc.
Columns must be identified by numbers, starting from the left. The first column must bear No. 1, the second column No. 2 etc. The indication of the coordinates on the microfiche is optional. If done, it should be done in the margins or in the lower area of the heading.
IV. 1. Information density (character concentration)
The dimensions of the computer generated microfiche images are a function of the apparent reduction.
The character density of an equivalent paper document is supported to be 60 characters by 6.45 cm 2 (inch squared), corresponding to a character pitch of 2.54 mm (0.1 ″) and a 4.23 mm (0.16 ″) line spacing.
When the coordinates are placed in the lower margin, they can interfere with automatic cutting systems that detect cut marks.
IV. 2. Quality requirements
First generation microfiche readability. Requirements
- A 12-line square matrix with at least 20 characters and symbols present in a random sequence must be registered in the center and in each corner of the entire image frame, including all the characters and symbols capable of being generated by the COM. Test samples must contain the information concentrated horizontally and vertically, representative of the maximum concentration expected. Each character or symbol thus generated must be able to be identified without error on a paper copy or on a reading screen. Test method. The magnification scale for printing or reading should not be less than 12X, so that the height of the smallest uppercase character is 1.6 mm (0.063 ″) maximum.The space between two successive lines of characters in the grid must not exceed 7/8 of the height of the uppercase letter E.
Alphanumeric COMs whose character height is between 2.28 mm and 2.54 mm (0.09 ″ and 0.1 ″) must use a maximum magnification for reading or printing of 16X for a nominal reduction of 1: 24 and 32X for a nominal 1:48 reduction of the system image.
The projection must be carried out with an approximate illumination of 540 lux.
- This test must be carried out systematically in order to achieve good quality control.
à Legibility of reproduction copies
The next generation that serves as a distribution copy must respect the same readability criteria as the first generation.
Convexity and curvature
A microfiche completely treated and cut in the distribution format must be placed with its convex side on a flat surface, for at least 6 hours, in an atmosphere whose temperature is 23 ± 2 ° C and whose relative humidity is 50 ± 5%, after which no part of the microfiche should be more than 6.5 mm above the surface.
Packaging
The microfiche destined for diffusion must be clean, dry and packed in such a way that they are suitably protected against any deterioration (eg in sealed plastic bags).
It is advisable to use reinforcing pieces in cardboard or fiber to prevent them from bending, rolling up or deforming.
Each microfiche, or in the case of microfiche below, the complete set of microfiches (maximum 4) can also be supplied in a paper envelope. In order for the indications in the heading to be read, envelopes must have a window at the top.
The paper used for the envelopes must be of a quality such as to protect the microfiche during storage and handling and must not contain chemicals that could damage them.
V. Microfilming process in the José Martí National Library
How is the microfilming process done in the José Martí National Library? This is precisely what this chapter will be about, since thanks to this process it was possible to really understand how it is done? What is does it ?, why is it done ?, how is its operation ?, among other questions; since only with the theoretical explanation provided by documentary sources is it not possible to fully understand it, that is why non-documentary sources were used, that is, it was necessary to rely mainly on the experience of the technical staff who reside in the José National Library Martí (BNJM).
Well, we will start by saying that the processing chamber used for microfilming in said institution is a FUJI brand from 1979, it is a whole unit, since it automatically performs all the processes: it copies, reveals, fixes, washes and dries the movie; in other words, it is a continuous process.
As this process is continuous, the microfiche changes by itself until it reaches the last one; this process lasts 11-13 minutes. The chemicals are prepared on the back of the equipment, placed in the box, the developer, the fixative and the water.
| Chemists using knobs | ||
| Fixative | A-3-24 500 ml | A-202 125 ml |
| Developer | A-87-1 500 ml | A-87-2 50 ml |
| Water | 4 Liters |
It is valid to clarify that the operator carries out all this process with the use of gloves and in the dark, thus preventing the photographic material from being veiled. The package of 50 microfiches is placed in the chasi moving it so that they take off, thus avoiding moisture, since when leaving it must be refrigerated.
When inserting them into the chasi, the microfiche must be placed with the shine upwards with the slot on the left. The refrigeration is not only to the microfiche package but also to the chemicals. After the microfiche is revealed, they are stored in an air-conditioned cubicle.
The intensity of the light depends on the coloring of the page and in order to determine adequate lighting. The density is measured in the dark parts, it must be 1.0 - 1.25 if the letters are very burnt out, this occurs in the density meter, a device that is used to measure it.
The processing machine has a “frame indicator” that is the same as the operator's sheet where it is guided, so if the operator makes a mistake, the machine should also discard the photographic material.
Every day this microfilming process requires a test by the personnel in charge of the material that works there, since the developer has chemical wear and tear as the fixative since any dust garbage could scratch the material.
The chamber is cleaned once a week and the chemicals are prepared again.
Currently at the BNJM only Cuban books are microfiched. Before starting the process, a technological chart is placed (see Annex # 2).
To measure the readability of the material (up to 8 streaks should be seen on the chart under a microscope, indicating that the material is visible).
Every time a microfiche is finished, the technology card must be put, this is done thanks to the fact that the operator is sitting near the processing machine to observe the clock that indicates that he is changing the microfiche and thus avoid confusion, double work and the disposal of the material. It should be clarified that the FUJI processing chamber used in the BNJM only books microfiche because of the format it presents with a scale of 22 cm.
When the book that is being microprocessed is finished, the last page is END, which is set by the operator so that the user knows that it is the end of the book. Newspapers and magazines undergo the microfilming process.
Everything in the book is microfiche, even the cover of the book in order for the user to see and feel that they have in front of them, the book itself, with all its parts.
Developer is used for the microfilming process, so 4 liters and 500 ml (4 ½ liters) of developer are needed to dilute it in water; the oven must be between 20 - 23 ° C temperature, if this temperature is exceeded the microfiche burns.
Once this information has been accumulated, the information that must be contained in it is reproduced, not taking it to paper, but to the so-called diazo, which is a silver film like the microfiche.
The microfiche is duplicated by contacting the silver film with the diazo exposed to the light intensity of a mercury lamp and developed with 25% ammonia fumes.
This process is done through the diazo duplicator (it works with ammonia salts).
The density in the negative should be between 0.89 - 1.25 and it is measured in the dark parts, this is depending on the type of paper of the document that is being microprocessed, for example: if the book paper, in this case, if it is yellow, it needs more light, but in case the paper is whiter, it would need less light when making the duplicate. The diazo is the one that is provided to the user for her work.
Finally, when the user goes to consult a document that goes to the catalog, at the time of delivery, the user is informed, in case of deterioration or loss, that the document cannot be loaned, but if he wants it You can consult through this support; in case the user accepts, they place it in a place with the conditions created for the loan of said service and thus the user can leave with the information he needs, since he can see the microfiches in the reader (this is the instrument by which they read the microfiches).
V.1. Considerations:
- Local with air conditioning 24 hours; Shelves separated from walls; Metal files; The microfiches must be placed in envelopes whose paper is acid-free, with a neutral or slightly basic pH, and no attachments in the envelopes containing the materials (both original and positive); This technique is more durable than digitized information, it can last up to 100 years; The information contained in the microfiches can be reproduced through the scanner.
SAW. Conclusions
- The use of microfiches has been of great importance because for years it has been possible to prove that their material is durable, so much so that they often use it to support documents that are of any importance to the user or to the nation. As it has been possible to appreciate they have common and unique characteristics that belong only to that type of technique that is carried out in it. Its conservation is not so expensive unlike other supports, however when it deteriorates its restoration is not possible, therefore it must be handled with extreme cleaning. They are also important, as they are capable of reducing space by 95%.
VII. recommendations
- That the service be maintained at the BNJM. That it be implemented in other centers, either in Havana City or in the various provinces of the country.
VIII. Bibliography
1. Maritza Dorta Valdés, Orlando Rubiera Valdés, “Microfilming teams; microfilms; microfiches and analysis of the Pentaka system ”, News of Scientific and Technical Information (March, 1982) 19-24.
2. Maylet Osorio Salgado, Leydis Sánches Hernández, “Conservation of microforms in the José Martí National Library” (Diploma Work, University of Havana, 1995), 30.
3. Maritza Dorta Valdés, Orlando Rubiera Valdés, “Microfilming teams; microfilms; microfiches and analysis of the Pentaka system ”, News of Scientific and Technical Information (March, 1982) 36.
4. Analysis and design of information systems.
5. Information and documentation manual on industrial property (December, 1990), ST.7 / F - 3.7.6.9
1 Maylet Osorio Salgado, Leydis Sánches Hernández, “Conservation of microforms in the José Martí National Library” (Diploma Work, University of Havana, 1995), 30.
2 Ibidem 1, 36
Maritza Dorta Valdés, Orlando Rubiera Valdés, “Microfilming teams; microfilm, microfiche and analysis of the Pentakta system ”, News of Scientific and Technical Information (March, 1982) 23-24.
