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Vol. 10(2), pp. 2-6The McAllen International Orchid Society JournalFebruary 2009

The Digital Divide -- Slide Film Restoration

Travis D. Whippie

Introduction

Despite the healthy dose of nostalgia, we have come to understand that film photography is limited in longevity, color depth, accurate color depiction, and resolution in comparison to the latest advances in digital image capture. Until 1995, slide film was the gold standard for any photography to be published. It was tack-sharp due to a higher photo resolution. Also, it produced a deeper range of rich coloration, and withstood the rigors or physical archiving better than a color negative film. However, the process is being faded out of modern photography as it becomes superseded by color corrective, high resolution sensors that can be used to capture the image at hand with more precision. This, of course, means we are left with a wonderful array of old scientific information in a seemingly obscure format that's both costly to convert and time consuming to organize and view.

The most serious limitations to slide film is its relative inability of correct color capture. This seems trivial at first, but trace the film photography steps from shooting the medium, to when the image is reproduced, to, perhaps weeks later, and there is an enormous capacity for error in color fidelity. The exposure might have been too weak, the shot might be taken in strange lighting, or the film may be balanced for the wrong end of the spectrum. In addition, the exposure to UV light, moisture, oxidation and the degradation over time of the active chemistry of these images assures us that during the 30 to 50 year life of these slides the colors will be fading and losing their glory. How do we then make certain these works never disappear and are presented in their full luminous colors for generations to come? Fortunately, digital restoration allows us a multitude of options to archive and preserve our fading media. Simply stated, a digital image is made from the film.

Restoring many of the color transparencies from the files of Lager and Hurrell fulfills at least a two-pronged purpose: it serves to archive the material in a format that is organized, and they become more available as figures for current publications. In addition, they serve as a record of many of the orchidists who contributed slides to John Lager's collection over the years. Now-historical names such as Goodale Moir, Rebecca Northen, and others are common.

Material

For this publication, the equipment used was the Nikon Super COOLSCAN IV ED slide scanner. This equipment is available for use with either a Macintosh or a Windows-equipped computer. For this work a Windows-equipped computer was used, and transparencies were saved at the highest quality level of the JPG format. Color transparencies used were selected from the files of the Lager & Hurrell Orchid Company which was America's first commercial orchid company, and operated from its inception in the early 1890's until closed by the third generation John Lager in 1979. At the firm's close, the colored slide file, the original hand-written day-books and ledgers, and other historical material was acquired by your MIOS editor. Now, after years of moves, domestic responsibilities, and even career changes, work is being done to restore 35mm transparencies, photographs, and do serious archiving of the entire collection, much of what is now one-of-a-kind historical material.

Methodology

Each slide is carefully cleaned of dust and oils and assessed for damage before being loaded. The scanner has a slot that accepts a single 2 by 2-inch slide, and, when initiated, automatically focuses its sensor and presents a preview of the scan with the current settings.

Fig. 1. Screen captured image of transparency. Barkeria naevosa (Ldl.) Schltr., Repert. Spec. Nov. Regni. Veg. Beih. 19:46 (1923).

We begin with a transparency annotated as "Barkeria naevosum; Mexico April, 1960." Our first action is then to note these data on a spread sheet, and verify, insofar as is possible, whether the name is valid. In many cases the genus name has been changed, and, with it, the specific epithet (to agree with the new latinized genus name). In this case, the genus is correct, but the species nomen was misspelled. The photograph was taken in 1960 of the orchid Barkeria naevosa (Ldl.) Schltr. 1923. The correct nomenclature of our specimen is indicated in the figure's text block. These data are noted on our spread sheet. We now look at the initial screen captured image of our slide (Fig. 1).

Fig. 1a. Initial jpg figure as it would print. Barkeria naevosa (Ldl.) Schltr., Repert. Spec. Nov. Regni. Veg. Beih. 19:46 (1923).

The computer screen displays the 35mm transparency without any color modifications. The exposure is less than optimal for a print and shows a distinct red color cast that skews all of the colors towards a faded maroon hue (Fig. 1a).

Fig. 2. Screen display with ROC and Digital ICE portions applied and indicated.

Fig. 2a. JPG figure.

We now get into the more technical aspects of digital work. The terms "ROC and "ICE" are acronyms derived from film-photography, but for our purposes it is sufficient to note that, in digital photography, ROC is used for color correction, ICE for dust and scratch removal; GEM is used for "noise" (grain) reduction. "ROC color correction" is an algorithm that attempts to ferret out, from the basic image, what the true black and white are of its specific setting. It then skews each color to represent its perception of the scene's color balance. This is a shotgun technique, but one that often gives an excellent starting point that only requires a bit of tweaking in either the curves or color balance settings. "Digital ICE" is a good method for reducing noise in the image as well as small scratches and impossible-to-remove dust spots. Thus, our first instinct is to select a post processing in our menu and preview the scan with an ROC color correction in place (Fig. 2) (Fig. 2a).

ROC has pointed out a very specific red color aberration due to slide degradation, potential heat damage, and poor initial exposure probably due to low lighting. The image is clearer, but lacks contrast, and color saturation, and it is a bit fuzzy as well. In a rush to recover a color transparency's figure and promptly use it in a publication, it may be tempting to use the above display. However, taking a little more time ensures that the best quality of digitalization is obtained, and when one is archiving material, the old saw of "haste makes waste" applies. Take necessary time with each slide, document, or photograph, and do the best job one's talent permits with the best technology available!

Fig. 3. Screen display with ICE, GEM, and Sharpening applied.

Fig. 3a. JPG figure.

Accordingly, we return to another screen capture to compensate for low color values and fading. The color balance is modified perceptually to bring out a vivid green leaf and the flower's distinct venation. Sharpening is utilized to make the image crisp, and the image's density is adjusted to make it brighter and more contrasted; thus less faded (Fig. 3) (Fig. 3a).

Results

Fig. 4. Initial scan of color transparency. Barkeria skinneri (Bateman ex Lindley) Paxton. Paxton's Mag. Bot. 15:1. 1849.

Fig. 5. The same transparency, post-restoration. Barkeria skinneri (Bateman ex Lindley) Paxton. Paxton's Mag. Bot. 15:1. 1849.

The following figures were produced from a color transparency labeled only "Nov. 1959" and "Barkeria skinneri." The first figure (Fig. 4) is from the slide's initial scan; as the slide looks to the naked eye. The second one (Fig. 5) received the full treatment as did the one in Fig. 3a.

Discussion

It is simple to build a systematic workflow out of the steps outlined above and expect high quality archives. With this system we are looking forward to preserving a massive collection of slides and photographs. The ultimate objectives are to retain the original material under conditions of high quality, and have both original and restored material in a CD, DVD, or some other comparable format available for scientists and serious orchidists for years to come.

Editor's Note: The Nikon COOLSCAN equipment and the color transparencies used in this article are from the Lager and Hurrell material which is part of the library of your editor and his wife. However, all the computer work, the color restoration work, and results of its associated technology are the sole products of the expertise of Travis D. Whippie. The work was done in McAllen, Texas and your editor was electronically furnished his text and jpg figures. Both individuals look to increased cooperation in archiving these and other materials.

Copyright © 2009 Travis D. Whippie