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

 

Manuscript

  • 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

 

Ratio

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

 

Resolution

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

 

Storage

  • 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

 

Reformatting

  • 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