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The MacKinney Collection of Medieval Medical Illustrations

About the Collection

  1. From Ektachrome to Digital: The Digitization of MacKinney's Slide Collection
  2. Copyright Information

From Ektachrome to Digital: The Digitization of MacKinney's Slide Collection

By the 1950's—when MacKinney began seriously building up his slide collection—several camera and film options existed for amateur photographers who wanted to maximize the potential of both black and white and color photographic technologies. Cameras became easier to use, transport, and adaptable to diverse lighting conditions. Thus, from 1945 through the 1950's, cameras intended for commercial sale benefited from smaller, more streamlined body designs, the development of eye-level cameras, built-in close-up lenses, and flash attachments and/or flash synchronization.1 More importantly for MacKinney's work, film technology also evolved to better accommodate the needs of those photographers aiming for slide projection of color images. In the 1940s, the Eastman Kodak Company developed a new kind of positive film to offer in addition to its existing Kodachrome film: Ektachrome. A chromogenic camera film (a kind of film which undergoes a developing process where chemical synthesis produces color2), Ektachrome was more appealing than Kodachrome film for projection due to its method for creating color. While Kodachrome films required dye-injection during development, Ektachrome films contained dyes already built into the emulsion (a mixture of two un-blendable substances on the photo-sensitive side of the photographic film). Built-in dyes allowed for a simplified development process and ensured reduced damage from exposure to projector lights.3

Despite their advantages over Kodachrome slides, Ektachrome slides (of which the MacKinney collection is almost entirely comprised) from their inception to the late 1960's had one remarkable disadvantage: poor dark fading stability. Although Ektachrome slides withstood projection-induced deterioration, they would fade even in dark storage at a much more rapid pace than their Kodachrome counterparts—at their introduction, Ektachrome slides could fade at least 20 times faster.4 Perhaps even more problematic was Kodak's failure to inform professional and amateur photographers of Ektachrome's far inferior dark fading stability.5 Thus, from 1946 to 1976, photographers using Kodak Process E-1, E-2, and E-3 Ektachrome films were producing unique color transparencies, but they were unaware that these films could also be subject to severe loss of cyan and yellow dye while in dark storage.6

Given the uniqueness of the MacKinney slides—they are originals that cannot be reproduced from a negative—and potential damage that could result from poor dark fading stability, fungus growth on the emulsion, and/or excessive handling (slides of any variety deteriorate from physical damage, dirt, fingerprints, and scratches), the digitization of MacKinney's collection provides users with replicas of the slides in their current condition while simultaneously protecting the originals. Stored in tightly-packed cigar boxes, the slide collection was initially given to UNC's Art Department by MacKinney's widow Abigail MacKinney shortly after his death. Not sure what to do with the collection, the Art Department contacted Michael McVaugh when he began teaching at UNC in 1964-65. McVaugh suggested giving the master set to the National Library of Medicine of Bethesda (where it still resides) and, since the Art Department had no use for it, took charge of the duplicate set. Over the next forty years they were occasionally consulted for various purposes, but they were not heavily used and astonishingly have suffered virtually no physical deterioration. While the MacKinney slides' physical integrity remains excellent, they display varying levels of discoloration, ranging from moderate to severe color shifts toward green and blue.7

Hoping that others might benefit from the collection and concerned about its long-term preservation, McVaugh instigated its digitization. The MacKinney slides were digitized from late June through August in 2007 using the Nikon SuperCool SCU 9000. In order to create a master archive of the images at the highest resolution possible, the slides were scanned five at a time at 4000 pixels per inch. Copies of these images were then adjusted in Photoshop; they were sharpened, cropped, and color adjusted. These manipulations of the digital images of the slides sought to represent accurately the condition of the original slide and to produce a natural appearance for screen-viewing.8

1 Brian Coe, Cameras: From Daguerreotypes to Instant Pictures (Gothenburg, Sweden: Crown Publishing, 1978): 97.
2 Henry Wilhelm and Carol Brower, The Permanence and Care of Color Photographs: Traditional and Digital Color Prints, Color Negatives, Slides, and Motion Pictures (Grinnell, Iowa: Preservation, 1993): 21.
3 This information on the differences between Ektachrome and Kodachrome films for slide projection courtesy of Keith Longiotti of the North Carolina Collection Photographic Archives.
4 Wilhelm and Brower, 25.
5 Wilhelm and Brower, 25.
6 Wilhelm and Brower, 26. From 1966 to 1977, amateur photographers had access to E-4 Ektachrome films, which were much more stable than the E-3 films used by professionals during the same time period. In 1977, Kodak replaced all previous Ektachrome films with E-6 films, guaranteeing equal dark fading stability for both amateur and professional films.
7 Information concerning slide condition courtesy of Jennifer Merriman and Bill Richards of CDLA - Digital Production Center.
8 This information courtesy of Richards.

Copyright Information

This site is intended for educational purposes. The manuscripts represented are not held by the University of North Carolina. Those seeking provenance, reproductions and permissions should contact the holding repository.

The scene above depicts a man surrounded by zodiac symbols. The image is a part of a manuscript held by the Fitzwilliam Museum in Cambridge, MS 167, folio 35v.
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