Record Type: Film Output from Motion Picture Film Source

Expected Use: Preservation Master

Product Name: DNT (Duplicate Negative Track) [MPA-P6]

Product Purpose: The purpose of this product is to mitigate risk for loss of information. This product is reproduced according to established industry standards and can substitute for the original record if the original record copy is no longer viable.

Nature of Source Material: 35mm or 16mm sound film elements, including MPT (Master Positive Track) or composite elements, where there is a need to ensure that all significant auditory information is carried forward. In some cases, an optical sound laser film recorder is used to output a DNT from a preservation-quality WAV (Waveform) file (Motion Picture Film Maximum Capture - Soundtrack Audio Data WAV [MPD-P6]). The WAV file may be captured from a MAG (Magnetic Track) element or an optical element.

Film Stock: Kodak 2374 (35mm), Kodak 2234 (35mm), and Kodak 3234 (16mm)

Other Information: 

  • Separate sound track elements may be combined with visual elements to make a composite element.
  • This product is placed in a cold storage (on or off site) environment and retained for the long term.
  • This product is created from the most original film copy.
  • This product is rarely accessed directly unless the reproduction master is damaged, destroyed, otherwise compromised, or does not exist.
  • This product is used to create reproduction master elements. It is never accessed directly by researchers and only sent to vendors under certain circumstances.
  • This product is known internally as the “Preservation copy” or “P copy” and usually has a red color swatch on the film can.

Quality Control


Control strips are created on a sensitometer for each new processing batch and evaluated on the densitometer. Adjustments are made to the processing chemicals as needed to achieve the desired neutral visual density reading of “1” on the control strip.

Methylene Blue Testing

ISO 18917: 1999 compliance: Methylene blue testing to measure residual thiosulfate and its decomposition products is of use in appraising the adequacy of washing and therefore the permanence of the silver image on photographic films, plates and papers. Inadequate washing can cause a loss in image density and the formation of stain in low-density areas.


For the most part, film-based product specifications are dictated by the source material’s film element type. There is some flexibility however in regards to combining separate picture and soundtrack reels into a composite reel. Selected image adjustments such as color correction and density correction are routinely performed during the reformatting process.