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Micrographics 101

Micrographics 101

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Micrographics 101

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  1. Micrographics 101 CRAC STAFF WORKSHOP IMAGING MARCH 15, 2011

  2. DISCLAIMER / WARNING This is a training workshop, but local practices do vary from county to county according to local policy and practice as well as local county counsel opinions. No practice or procedure you become aware of as a result of this workshop should be implemented in your own office without the full AWARENESS and APPROVAL of the County Clerk or Recorder for whom you work.

  3. Microfilm Formats • Roll - 16mm and 35mm • Cartridges • Microfiche - Jackets • Microfiche - Step & Repeat • Computer Output Microfilm (COM) • Aperture Cards

  4. Microfilm Types • Silver Halide • Camera Negative • Silver Duplicate • Acetate Base - LE100 • Polyester Base - LE500 • Suitable for “Archival” Storage

  5. Microfilm Types • Diazo • Duplicating Film used for making same polarity “working” copies • Processed using Ammonia • Not Suitable for “Archival” Storage • Comes in Black, Blue-Black & Blue Colors

  6. Microfilm Types • Vesicular • Duplicating Film used for making reverse polarity “working” copies • Not Suitable for “Archival” Storage • Comes in various colors

  7. Silver Halide Microfilm Processing • Requires a film processor with toxic chemicals • Polysulfide Toning will increase resistance to redox • Processing needs to be monitored for quality • Consistent Density • Scratches, Water Spots • Regular Methylene Blue Testing

  8. Storage Conditions • “Archival” Enclosures • Plastic Boxes - pure polypropylene or polyethylene • Acid-free, lignin-free paper boxes • ISO 18902:2001 - (formerly ANSI/AIIM 9.2-1991)

  9. Storage Conditions • Climate Control • Temperature - 70º F or LESS • Humidity 30-35% RH • Minimal variation within a 24 hour period - 5% • ISO 18911:2000

  10. Storage Conditions • Pollution • Formaldehyde - carpeting, insulation, synthetic fabrics • Ozone – smog, copiers, laser printers • Peroxide - breakdown of paper fibers (Lignin) by acids

  11. Microfilm Degradation • Redox • Appears as red spots or silver “sheen” on the emulsion side of the film • Most commonly caused by Peroxide gas released from low quality microfilm boxes • Can also be cause by atmospheric pollutants listed above • Effects both Acetate and Polyester Films • Removing the source of the oxidant will halt the problem, but it can’t be cured • Prevention is the key

  12. Microfilm Degradation -Redox Photos

  13. Microfilm Degradation • Vinegar Syndrome • Affects Acetate base film only - Polyester film is immune. • Acetate film stored properly should last 100 years before the onset of symptoms. • Acetate base degrades with time, temperature and humidity - releasing Acetic Acid which causes the base to shrink and warp. • Higher temperature and humidity will accelerate the process. Once the Vinegar smell begins, colder temperature/lower humidity will slow down the process but it is irreversible. The only solution is to make a silver duplicate on polyester film before the damage becomes too great.

  14. Microfilm Degradation - Vinegar Syndrome Photos

  15. Microfilm Generations • Camera Negative - 1st Generation - readable looking at base of the film • 2nd Generation - duplicate made from the Camera Negative - readable looking at the emulsion side of the film • 3rd Generation - duplicate made from the 2nd Generation - readable looking at the base of the film • etc.

  16. Silver Halide Microfilm Structure • “Older” microfilm has an acetate base • “Newer” microfilm has a polyester base From Keeping the Legacy of Trust by Robert Breslawski - Eastman Kodak Company

  17. How to determine the emulsion side • The emulsion side of the film is duller than the base side • Look at a dark section the film in reflected light and compare the two sides • If you can’t tell which is the dull side: • Lip Test - emulsion side will stick to your lip, the base won’t • Scratch Test - a deep scratch on the emulsion side will remove the emulsion (do this far away from any images, please!!!!)

  18. Film Polarity • Negative - white letters on a black background • Positive - black letters on a white/clear background • Photostats - see the next slide there isn’t enough room on this one!!

  19. Photostats - the original • The original “photocopy” process • A full-size photographic reproduction of the original document • It was a “wet processed” photographic negative • The original document was returned to the owner. The Official Record was a photographic, negative paper copy - white letters on a black background

  20. Photostat of an Official Record Document

  21. Photostats microfilmed • By definition, “normally” processed microfilm is a “negative” copy of the document that was filmed (“original”) • However, in this case, the “original” was a “negative” • A negative of a negative is a positive - -2 X -2 = +4 • So microfilmed photostats are “negatives” that appear “positive” • Got it??

  22. Film Examples Negative film - note the film is clear between the frames Positive film - note the film is black between the frames Photostats - documents appear positive, but the film is clear between the frames

  23. Final Thoughts • Always handle film by the edges and wear gloves • Camera negative film should never be used as a “working copy” • Camera negative film should be stored in a secure, climate controlled vault • Camera negative film should be stored in proper “Archival” boxes • Don’t put camera negative film in cartridges • Do you know where your film is?