Microfilm Terminology

Preservation Microfilming

  • Techniques associated with the production, handling and use of microforms
  • Creating Microfilm to current ISO Standards that ensures LE ( Life Expectancy) of 500 years


Microform Types

  • Roll film/reel (16/35mm)
  • Microfiche (105mm)
  • Aperture Cards
  • Cartridge based roll film


Microfilm Generations

  • Master (1N)
  • Duplicate Negative (2N) or Negative Intermediate
  • Duplicate Positive (2P) or Positive Intermediate
  • Service Halide Positive (3P) or Copy Positive
  • COM– Computer Output Microfilm or Digital Microfilm


Legacy Microfilming

  • Generally films created before ISO Standards established or implemented. Can be found on Polyester or Acetate


Acetate Breakdown


Darkroom Processing

  • Generic term for silver-gelatin films; a series of steps principally including developing, fixing, washing and drying


Modern Newspapers

  • Papers generally published after 1990



  • Generally bound Books, Diaries, Journals, Serials or loose sheets, varying ink qualities and colours, often have handling issues and varying degrees of conditions


Cine Mode

  • Original document filmed landscape
  • The lower the ratio the better for text legibility, highly suited for retro documents, average frame count for each reel is 500 images.


Comic Mode

  • Original document filmed portrait
  • Suitable for filming of modern papers, filmed at a higher ratio as typeface is generally of good quality and high contrast, average frame count for each reel is over 1000 images



  • Relationship between the dimensions of the original and it’s micro image reduction



  • Focus achieved at time of capture, governed by ISO Standards



  • Storage requirements of original documents and all generations of microfilms will determine their Life Expectancy


Planetary Camera

  • Method of microfilming where the document and the film are stationary during capture


Rotary Camera

  • Method of microfilming where the document and film are in synchronised movement during capture



  • Transferring information from one format to another e.g. Acetate film duplicated onto Polyester
  • New generation of polyester film then becomes the PDM (Preservation Duplicate Master)


OCR or Trancription

  • Optical Character Recognition (OCR): convert an image into searchable/editable text using software
  • Transcription: convert an image into searchable/editable text using keyboarding