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Microfilm: Disaster Solution or Simmering Disaster?

Microfilm: Disaster Solution or Simmering Disaster?. NACRC July 15, 2011 Jim Harper, President PFA, Inc. Where is the Disaster?. This is a picture show about the microfilm all of you have in one or more forms. The disaster is in the vault and in our heads.

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Microfilm: Disaster Solution or Simmering Disaster?

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  1. Microfilm: Disaster Solution or Simmering Disaster? NACRC July 15, 2011 Jim Harper, President PFA, Inc. PFA, Inc. - www.pfainc.com

  2. Where is the Disaster? • This is a picture show about the microfilm all of you have in one or more forms. • The disaster is in the vault and in our heads. • Ignorance – we’re losing our micrographics memory. • In hind sight, some microforms were chosen based on ignorance and short term planning. • Neglect – we haven’t done what we’re supposed to do.

  3. Microfilm Basics • A Brief History • “Microphotography” invented in 1839 • Suggested for document preservation in 1851 • First used commercially in the 1920s • Patented in 1925 • Purchased by Kodak in 1928

  4. Microfilm Cameras

  5. Microfilm Resolution Target The page reduction ratio X the lowest number where you can see distinct separation = resolution in lines/mm.

  6. Microforms

  7. Common Roll Formats 35mm on open reel 16mm on camera reel

  8. Microfilm Jackets • Rollfilm cut into strips and slid into sleeves • Not the best choice for preservation or recovery. • Often the camera film is in the jackets

  9. More Jacket Formats

  10. COM Microfiche

  11. Aperture Cards

  12. Film Generations • The film used in the camera is called: • Camera Negative • 1st Generation • Silver Original • Silver Master – not a definitive description • If you can read words looking through the base side, it’s an odd generation. • If you can read looking through the emulsion, it’s an even generation. • Should not be a “mirror image”.

  13. Film Types • Silver Original – Preservation – offsite • Silver Duplicate – In-house printing master • Diazo Duplicate – Working copy • Direct Duplicating film makes a same polarity copy • Print film makes a opposite polarity copy

  14. Film Base Types Acetate Base Polyester Base

  15. How to Tell Film Base Types – Backlighting Acetate Base – Bad 1980s & Prior - tears easily Polyester Base – Good 1980s and After This film tears only if nicked

  16. Film Emulsion • Silver film: shinny side is the base & dull side is the emulsion. • Lip test: Put the end of the film leader between your lips. The sticky side is the emulsion side. Beware of splices! • Diazo film has an emulsion side but its hard to determine without scratching the film.

  17. “Cosmetic” Redox (Measles) – All Silver Film Oxidation of the silver halide.

  18. Problem Redox - All Silver Film

  19. Oxidant Sources & Other No Nos

  20. Polysulfide Film Treatment • Protects the silver from oxidation. • Can be done during or after processing in a processor with an extra tank to accommodate the toner.

  21. Vinegar Syndrome – Acetate Film

  22. Microfilm Splicers Prestoseal - Acetate Metric – Polyester Pre 1980s film Post 1980s film

  23. Tape Splicers – Sometimes A Necessary Evil Guillotine Tape Splicer Optically Clear Mylar Tape 1/8” – 1” widths

  24. Microfilm Inspection This…. Not this….

  25. Microfilm Recorders Kodak Archive Writer Fuji AR1000 PRIA Best Practice!

  26. Optical Media Oxidation CD Rot DVD Rot

  27. Optical Media Oxidation Blu-Ray Disc Rot Media Layers

  28. MAM-A Transfer Media

  29. The Future of Electronic Preservation • CAS – Content Addressable Storage • WORM – Write Once Read Many • Self Auditing – Secure Hash Algorithm version 2, 512 bit • Self Repairing – Reed Solomon error correction • Automatic email error notification

  30. References • Film boxes must meet ISO 18902:2007 • Photographic activity test – ISO 14523:1999 • www.centuryboxes.com • Silver microfilm • Environmental storage conditions – ISO 18911:2010 • Polysulfide toning of microfilm • Testing method – ISO 18915:2000 • CDs & DVDs • Environmental storage conditions – ISO 18925:2002 • www.mam-a.com • PRIA Archival Backup & Disaster Recovery Workgroup • www.pria.us/i4a/pages/index.cfm?pageid=3308 • Vinegar Syndrome detection strips • https://www.imagepermanenceinstitute.org/imaging/ad-strips

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