What Kind of Microfilm do I Have?
We get a lot of questions from folks who have documents on microform but are not sure exactly what they have. Hopefully this post will clarify things a bit.
Creekside Digital can scan all of the following major types of microform:
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Rollfilm. As its name implies, rollfilm is a roll or spool of film containing a sequential series of frames. It comes it two widths: 16mm and 35mm. Typically, one finds rollfilm in lengths of 100′ or less.16mm rollfilm is the “typical” film width used for office-sized 8-1/2″ x 11″ / A4 documents. At 24x reduction ratio, it’s possible to fit about 2,500 documents on a 100′ roll of microfilm. One often finds check stubs, time cards, bills and invoices, and similar documents on this type of rollfilm. The frames can be quite small, especially with duplex microfilm (which captures both sides of each original document), so care and quality equipment are required to get sharp images which are true to the original. Sometimes spools of 16mm rollfilm will be enclosed in a square, open plastic frame to allow them to work with a specific microfilm reader / printer — but they will still have the same type of plastic spool and hub shown here.
35mm rollfilm is used where larger frames are required due to bigger source documents. It is very popular for newspapers, architectural drawings, and engineering diagrams. Even lighting and quality optics with a wide depth-of-field are required to ensure there is no darkening or bluriness around the edges of the frames. 35mm rollfilm is also the film of choice for archiving older historic documents at a lower reduction ratio so the larger frames can be used to capture the original document at a much higher resolution.
3M cartridges are essentially 16mm rollfilm in a square, hard plastic case or “cartridge.” Rather than a single square hole in the middle of a plastic spool, 3M cartridges have a metal hub with four smaller, round holes. They often require a special adapter to allow them to be loaded onto a scanner, which not all vendors have (yes — Creekside Digital can work with 3M cartridges). Other than their cartridge format, 3M cartridges are identical to normal 16mm film in terms of what types of documents they’re typically used to store.
- Microfiche. Microfiche comes in several different types:
Jacket microfiche are strips of 16mm or 35mm film stored in a clear Mylar jacket or envelope. Jackets are typically 4″ x 6″ and can hold up to six strips of film, such that a matrix of images is created. A header strip across the top of the envelope will usually have the fiche’s title and indicate its contents.COM microfiche is typically used for technical manuals, parts lists, operation handbooks, etc. These are 4″ x 6″ sheets which have small individual frames arranged into a permanent grid pattern. Each sheet will have a header which has a title and describes its contents. COM fiche usually uses a higher reduction ratio (up to 50x or more) and a single sheet can hold up to 300 frames.
- Aperture Cards are punch cards (Hollerith cards) which have a single 35mm microfilm frame mounted in them. Aperture cards are typically used in engineering applications. The actual punch card portion of an aperture card may also contain index information about its image.
The bottom line: Creekside Digital can convert all of the above types of microform into digital images that you can view, email, and print from any PC. Still have questions about what type of film you have? Contact us!