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What Type of Film Do You Have?
EXAMPLES OF ROLLFILM
Microfilm is a 16 or 35mm photographic film with protective lightproof backing wound onto a spool. It resembles movie film but without sprocket holes and usually wound onto a metal or plastic spool and stored in a cardboard or plastic box. Microfilm contains all kinds of images such as documents, newspapers, plats, and maps. In the sections below, we have illustrated and described the different formats of microfilm so that you can correctly identify your film type.
These numbers refer to the width of the film. A 16mm roll of microfilm is 0.63 inches wide and will generally be 100ft or 215ft long depending on film thickness. Based on reduction ratio a 100ft roll will contain approx 2,500 images while 215ft roll will contain about 5,500.
A 35mm roll of microfilm is 1.38 inches wide. It will normally, but not exclusively, have images of larger documents like maps and newspapers. An average image count for a full 35mm roll is approximately 600 images.
Negative rolls have black boxes (frames) with the text being clear. No matter whether you have positive or negative rolls, after scanning is completed, all of the delivered images will be white pages with black text and the extra background will be cropped out.
A positive roll has clear frames, black text, and a black background. No matter whether you have positive or negative rolls, after scanning all images will be white with black text and the background will be cropped out.
Comic mode is portrait pages placed on the film left to right; the short side is horizontal and the long side is vertical.
Cine mode is landscape pages placed on the film left to right. The long side of the page is vertical while the short side is horizontal, similar to movie film.
Simplex film is single pages placed one after another with an even space between each frame, so there is no grouping or stacking.
Duplex film has a pair of frames either side by side or stacked on top of each other. These are normally the front and back of a document page.
Single Level Blip
Single level blips have little uniform squares or rectangles above or below each frame and tell the scanner that each page is separate document. The key difference is that single level have uniform blip size, multi-level has varying blip sizes.
Multi Level Blip
Film with multi-level blips has a variable sized rectangle above or below each frame. Usually having up to three different sized blips (small, medium, and large), they are typically used to indicate the start of a page, document, or folder.
COM = Computer Output to Microfilm
COM film is generated using a laser to write the images to the microfilm. It can resemble computer printer forms as both continuous or individual pages.
EXAMPLES OF MICROFICHE
Microfiche are flat sheets of film containing images for any size page or document. A single fiche contains a varying number of images organized into rows and columns with a place for the index data on the top edge.
4.10" x 5.85"
4.10" x 6.0"
5" x 8"
COM fiche is written by a laser. It typically holds large reports or manuals. Some documents may have a natural border while others will not and can be difficult to detect. COM uses a grid pattern to store the images. The grid may organized horizontally or vertically.
Single Frame (105mm)
There is only one, typically large, image on the fiche card
Step & Repeat
Step and repeat fiche is produced on a machine that holds the whole 105mm fiche. It then exposes a small area for a frame and then moves the fiche sideways to expose the next frame. Step and repeat normally has 96 frames in 6 rows on a clear background.
Microfiche Jackets come in all forms and sizes. They contain one or more sleeves that strips of microfilm are loaded into. The most common form is 5 rows of 12 frames making a 60 frame jacket. However, once the original jacket is produced they are frequently duplicated onto a single sheet of 105mm fiche.
Vesicular has a distinctive baby blue color throughout the whole fiche. It’s made with heat, so it is best to keep it away from heat sources as that will degrade the fiche. Vesicular film is cheap to produce and it requires no developing so it is a popular options for many organizations.
Silver Halide fiche have a dark-black color with a faint silver tint. Silver Halide is the most sensitive of all the fiche, meaning that is offers the highest resolution and depending on type, can record a greater variance of density and contrast present in the original material. This is the only fiche that is considered archival. When properly processed and stored, it has a life expectancy of about 500 years which makes it ideal for longevity and quality.
Diazo fiche has a dark blue or black color and no silver tint. It is typically used to generate working copies of the master fiche, like Vesicular, so that the originals are rarely handled. It is a cheap and easy way to make duplicate copies of your microfilm originals. IImage Retrieval digitizes Diazo film in our DFW location with extra care so they are not degraded.
EXAMPLES OF APERTURE CARDS
Aperture cards are a derivative of the original IBM punch card with a window cut into one side for a single frame of 35mm microfilm. The aperture card may or may not have Hollerith Code (punch holes with index information) but will normally have index data printed on the physical card's title strip. Aperture cards are commonly used for engineering drawings and other large documents but may also have multiple smaller pages in the large frame.
Coded Hollerith cards have punched rectangles throughout the card; each card varies in what areas are punched.
Single frame has one frame in the cut-out window.
Positive film has a transparent page with black text.
Uncoded cards are smooth and without punches.
Multiple images are placed onto a single large scan surface. They may be in a grid or randomly organized within the single frame..
Negative film has a black page and transparent text.
IImage Retrieval looks at the text information on the top of the fiche card to get indexing information, usually this will be a number or descriptive information on the title bar. Simple indexing is included in a project, however if you require more complex indexing, IIRI offers image level indexing where requested information on the scanned images can be used to name documents, images, and image folders.
IImage Retrieval includes roll level indexing at no additional cost. We will create one folder per roll named by the information located on the rollfilm box. Then, the images within that folder are numbered sequentially, 0001-####. For an additional charge, IIRI offers image level indexing where requested information on the scanned images can be extracted to name documents, images, and image folders.
Index information is typically taken from the unique identifying markers found at the top of the aperture card. Simple indexing is included in a project, however if you require more complex indexing, IIRI offers image level indexing where requested information on the scanned images can be used to name the scanned files.
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