Colour Transparencies

Type of Document

  • Slides larger than 35 mm; e.g., 120 mm, 4 x 5, 8 x 10, etc.)

Notes

  • Placement of the emulsion side varies from one scanner to another. To ensure that it is against the proper face of the optical reader, follow individual scanner guidelines.
  • Concentric ring patterns (dark and bright bands) may appear while scanning negatives. These patterns are called "Newton's Rings", and are caused by the interaction of light waves reflecting on two glossy surfaces - one convex and one flat - and the air pockets between them.
  • Possible ways to avoid them:
    1. Use a mount to raise the negative, thus avoiding contact with the scanner glass.
    2. Insert an anti-Newton's ring sheet between the negative and the scanner glass.

Remarks

  • The technician must verify the final image by comparing the original negative with the digitized version.
  • Batch digitization enhances productivity, but does not offer optimal rendering of individual images.

Procedures

  • Verify the film type. If the scanner offers this option, select the appropriate film profile and apply it to the digitization session.
  • Ideally, the colour scale used should be identical to the film type (e.g., Fuji film digitized using a Fuji scale).
  • If the type of film is unknown, do test scans to optimize digital rendering of the image.

Recommendations

  1. 300 ppi, with a minimum of 3,000 pixels for the longest measurement (8 x 10, or 1:1 for formats larger than 8 x 10).
  2. Refer to the general guidelines to calculate the number of ppi required for a given dimension.
    Note that it is the original document which measures 8 x 10, not the final digital file.
  3. Digitize in transparency mode.
  4. For reference purposes, digitize a transparent colour scale (on film) before each digitization session.

    Colour photo of six colourful handicrafts
    CD94-685-006
  5. If the transparency allows, reframe the image in a way which preserves the border and any notations found there.
  6. Balance the white levels in the whitest zone (D-Max), then balance the black in the blackest zone (D-Min).
  7. Convert in Adobe RGB 1998 profile, 8 bits per channel (total 24 bits).
  8. Save the image as an uncompressed TIFF, named to standards established by the Corporation's Photo Archives.
  9. Produce a JPEG version as described in the general guidelines.

Contact information for this web page

This resource was published by the Canadian Heritage Information Network (CHIN). For comments or questions regarding this content, please contact CHIN directly. To find other online resources for museum professionals, visit the CHIN homepage or the Museology and conservation topic page on Canada.ca.

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