Digitization Guidelines

This page provides guidelines for digitizing materials for finding aids and Digital Archives.

Goals

  • Increase visibility of archived materials to the public.
  • Support online, print, and presentation usage of digitized materials.
  • Manage the quality of materials that could be copied by the public without permission.
  • Create redundancy to protect materials from loss.
  • Adopt practices that are practical and cost-effective for part-time volunteers.

Digitization Levels

Within each collection, digitization can occur at the following levels. Different levels may be applied to various parts of a collection. (It's up to the archivist to decide.)

  1. No digitization: Finding aid describes items verbally (if at all).
  2. Low-resolution reference images: Up to 1/2 megapixels in size. Could be published online individually or in a PDF finding aid.
  3. Medium resolution (1 to 2 megapixels each). Suitable for presentation use. Also suggested for album pages published in a PDF finding aid.
  4. High-resolution, publication-quality images: Typically 8 to 16 megapixels, sufficient for print, presentation, and online use.

If we want users to contact us before using images, we should restrict online image size (individually or as part of a PDF finding aid) to low resolution images.

Scanning

  • To determine total resolution, multiply the image height (in pixels) by the width (in pixels). A scanner's dpi (dots per inch) is the same as pixels per inch.
  • Example: At 150 dpi, a 4x5in print would produce a scan of 600 by 750 pixels or 450,000 pixels (0.45 megapixels).
  • Here are some recommended scanner settings for print, presentation, and online use. You can adapt for different size originals.
Original FormatHigh Res (Print)Medium Res (Presentation)Low Res (Online)
35mm slide2400 dpi800 dpi600 dpi
6x6cm negative1200 dpi400 dpi266 dpi
4x5in neg/print800 dpi260 dpi150 dpi
8x10in print400 dpi150 dpi72 dpi
  • Avoid overly light or overly dark scans. Use the preview feature of your scanner to inspect the tonal range (histogram) of the scanned images. Adjust the scanner settings if the histogram indicates that light or dark areas are being badly clipped (crashing into the end of the range, see reference).
  • High-quality (low compression) JPEG files are recommended for archival. For an 8 to 16 megapixel image, a high quality JPEG will typically require from 4 to 10 megabytes of disk storage. JPEG compression is independent of scan resolution and it is determined by a quality setting (usually 0-100) offered by your image processing software when you save the JPEG file. A quality setting of at least 90 is recommended.
  • TIFF and other uncompressed formats are okay, but not required or recommended. TIFF files are several times larger than JPEG files, without clear benefits in quality for our use.
  • Original scan files (especially JPEGs) should be treated as "digital negatives" and never overwritten. For editing, make a copy of the original and edit the copy. This eliminates a key concern about using JPEGs--that repeated overwriting will degrade image quality. (If you need to make several editing passes on an image, save your intermediate copies as TIFF files. See reference.)
  • Look at the back and/or any packaging. Include any identifying information in the file name or use a photo editor that lets you put it in the IPTC caption field. If there is a lot of writing scan it too.

PDF Finding Aids

  • To make it easier to view a collection of images, consider combining images into a single PDF file.
  • PDF finding aids should be uploaded to the Mountaineer Archives wiki (this site) to enable the public to browse our digital materials. (The Mueller, Simmons, Swanson and Venema albums on our Collections page are good examples.)
  • Creating a PDF file with several images requires PDF authoring software. There are many freeware and commercial alternatives. (Nitro PDF, a commercial product that is less expensive than Adobe Acrobat, works well.)
  • Individual photos included in a PDF finding aid should generally be low resolution, to minimize the overall size of the file on line and to discourage unauthorized copying (if that is a concern). If you've scanned the images at high resolution (publication quality) you'll need to reduce them for use in a finding aid. (IrfanView, a free image viewer and editor, provides a batch conversion feature for resizing images.)
  • For album pages that consist of a collage of several images, use a medium resolution scan of the entire page, to enable closer inspection of each image.
  • It is not necessary to include all of a collection's images in a finding aid. It's okay to include just the most interesting ones. (It's a good idea to note this in our online catalog.)

Archival Disks

  • The Mountaineers Archives have a pair of 2 terabyte USB backup disks to be used for high-resolution digital materials. (See the Digital Archives page.)
  • High-resolution, publication-quality images should not be stored on the Mountaineer Archives wiki (this site).
  • Archival disks are stored in different locations (currently one at the Magnuson Park program center, the other at Lowell Skoog's house) for greater security.
  • Digital materials (including PDF finding aids) should be saved on both disks. The contents of the two disks should be identical.

Labeling on the Archives Wiki (this site)

  • Image files (individual images or PDF finding aids) should be named using the accession number (and specific item number if needed).
  • Example: MTR.2015.9-photos.pdf
  • The image file(s) should be uploaded to the wiki and inserted onto whatever catalog page you create.

Labeling on Archival Disks

  • Required: All scans for a given collection must be stored in a separate disk folder that indicates the name of the creator or the collection.
  • Recommended (but not required):
    • Include the name of the creator or collection in each file name.
    • Include additional information (like the negative or print number) in each file name.
    • Include descriptive information (like the date or names of people) in each file name.
    • Example (from the Spring collection): Spring-001384 - Ira Spring belays on Mt St Helens, 1948.jpg
  • Avoid relying on metadata in archival files. (We're not that sophisticated.)
  • The disk folder should contain a README.txt file that describes the contents, for example:
    • Creator or collection name
    • Mountaineer Archives accession number
    • Notes about the collection (for example, donor, background information, and whether some materials were not scanned)