Microfilming is an archival technique based mainly on changing the support of paper documents, in another that can be a synthetic material. Normally it is a tape of 30.5 meters of a flexible plastic material and very resistant to aging, on which a layer of photographic type material of the highest quality has been deposited. In this tape the documents are photographed with strong reductions, without losing some information. From this reduction or mini-aa-turization of size derive all the applications and, therefore, its great advantages that are:
- Substantial space savings (over 98%)
- Saving of archival items (cabinets, shelves, folders, etc.)
- Quick access and location, and agile consultation.
- Security derived from the fact that being of smaller volume it is simpler and cheaper to ensure the documentation against theft, fires, insects and rodents, etc.
- Security in the conservation of information and documents, since these in the microfilm are inaddulterable. You cannot modify the information.
- Microfilm is easier and cheaper to distribute and reproduce, because a copy of the microfilm costs very little, and being small in size, it has little freight or shipping costs.
- In normal formats it is possible that each roll of 16 mm microfilm can contain 2,800 official-sized documents, 5,600 letter-sized, and more than 11,000 the size of a check, and this on both sides.
For the recovery of the images from the microfilm only a device that basically consists of a microscope lens that projects the image of the film on a screen is enough. The search for documents is usually helped by a computer, which is the one that keeps in memory the positions of the documents contained in the rolls. If you want to rescue information you can do it through the screen, but if you want to restore the document on paper, you can do it by means of a common paper printing reader, which fulfills the two functions: show on the screen and print on paper a copy of the document shown. Usually the reading equipment or printing readers are simple and economical. They do not require most maintenance, and the inputs are reduced to paper and tonner in the printing readers.
Microfilm rolls can be stored indefinitely (their duration is estimated at 500 years in accelerated aging tests). Normally used in the visualization, a diazoic copy (very economical), and the original is saved. This is only used to make working copies.
THE TECHNIQUE OF MICROFILMING BY DIRECT COMPUTER OUTPUT – ( C . Or. M . )
Computer Output Microfilm, is a document archiving technique, which consists of microfilming all the data that is generated in a computer and that has output by printer. So, instead of generating the listings on paper, they are printed directly on microfilm, with the consequent saving of money, time and space, since 270 sheets of printer of 132 columns can be contained in a small microfiche of only 10 x 15 centimeters.
The systems called COLD, is a mixture of C.O.M. microfilming and digitization. The print Spool is written by means of a complex software on Ã"PTICOS DISCS or CD-ROM. The image can be viewed on computers, but at the same time multiple search operations or mathematical calculations are possible. In this way the image is transformed to be visualized into data that we can submit to various treatments and selections.
