Archiving

GLASS LANTERN SLIDES

Each image featured in the GALLERY was scanned directly from the original glass slide using a transparent lid scanner. Unlike traditional scanners that can only project light from the scanner bed, a scanner with a built-in transparent lid gives the user the option to use back lighting (like a light box) to illuminate reflective transparent images. The usage of back lighting allows the full detail and vibrancy of the glass slide image to be captured while eliminating any issue of reflection or glare off the glass cover plate.

After a scan is complete, the high-resolution digital image is then carefully processed to remove dust, scratches and other imperfections present on the original slide. All slides in this collection are in good condition and only require light digital touch-up once scanned. The objective is not to remove every speck of dust and minor flaw, but to remove only that which is deemed visually distracting or compromising to the integrity of the image. The philosophy is that the slight imperfections and inconsistencies associated with glass plate photography are part of the antiquity and charm of the original product.

Slides with typed and hand-written labels

It is important that these images retain their original characteristics: ie. highlights, mid-tones, shadows, colors, saturation, depth of field, warmth, grain, vignettes, etc. It is for this reason that we do not digitally adjust individual areas of color or tone within a particular image. The only contrast and color/tone adjustments that may be applied are done so across an entire image. Since digital scans in rare cases exaggerate or misinterpret true contrast and tone, certain color-correction techniques may be mindfully utilized simply as a means to represent a slide true to its original appearance. Individual areas of an image are re-touched only where damage has occurred to the original slide. With exception to contrast adjustment on more faded images, no significant alterations have been made to these images.

Hand-tinted glass lantern slide showing figurine painting in Germany, as photographed directly on a light box (uncropped) - Pub. by Underwood & Underwood

In the very rare case where a scanned slide is more heavily altered, the specific alteration/s made to the scan will be disclosed fully in the image details. This may include but is not limited to, bringing a color slide into black & white, extreme cropping, moderately adjusting contrast levels, etc. Sometimes alternations like these are necessary in order to create visual continuity between multi-image single prints or a print series. While these practices are not ideal, in rare cases they must be employed. All significant alterations are fully disclosed, so that the viewer knows exactly what is original to the image and what has been changed.

The intention is to present these slides as close as possible to how they appeared when they were first created and published to the world. Our philosophy is to best represent the original artistic works and not embellish or otherwise add to the original product. The aim is not to highlight the capabilities of digital technology, but rather, to exhibit the inherent capabilities and overall beauty of the antique dry plate medium and the glass lantern slide format in particular. The original images speak for themselves and rarely need any enhancement.

HAND-TINTED vs. HAND-PAINTED

Hand-tinted: referring to slides that are more lightly color toned and do not exhibit visible brush strokes

Hand-painted: referring to slides that exhibit brush strokes and thicker or more prominent paint layers - resembling a cross between a photo and an oil painting

While these two terms may be synonymous with each other in the field of glass slide collecting, it is simply the preference of this archive to establish a clear distinction in definition for descriptive clarity.

Hand-tinted antique glass slide (Niagara Falls, USA)

Hand-painted antique glass slide (Callander Bridge in Scotland)

APPROXIMATE SLIDE DATING

In the case that a slide does not have a date designated on the label, a production date must be approximated. This can be done by examining the subject/s of the image itself (ie. clothing, hairstyles, general scene, etc.) and by inspecting the thickness of the glass plates. The thicker the glass, the older the slide likely is.

It's often the case that a slide will be cataloged and dated in other collections/registers even if the particular copy in this collection is not dated. With minimal research, precise production dates can sometimes be determined. Commercially produced slides are generally much easier to date than those published privately. Some privately produced slides are so rare that it may be difficult or impossible to ever find another copy.

Two glass lantern slides of different ages - The thicker slide (top) is circa. late 19th century and the thinner slide dates to the early 20th century.

SAFE CLEANING

Prior to the scanning of any glass lantern slide, both sides must be thoroughly cleaned to remove all visible dirt, dust and debris from the face of the glass. This is done by the application of glass cleaner to the tip of a diamond-weave, micro-fiber cloth that is designed to clean efficiently while eliminating any leftover streaks and residue from the application process.

When cleaning glass plate negatives (where the photographic emulsion is exposed to the air) it is important to use an archival-safe, non-ammonia-based cleaner. But because the lantern slide emulsion is essentially sealed off to the outside environment, stronger glass cleaners with ammonia can safely be used with caution in most cases. Archival-safe cleaner (ie. PEC-12) will be insufficient in thoroughly cleaning glass if the particular surface residue is water-based.

Cleaning lantern slides takes great care and attention, as to limit the application of the cleaner to the glass only, avoiding any contact with the hand-written labels and edge tape. Sometimes it's difficult to distinguish small scratches or flaws in the glass from surface debris. It takes a careful eye to diligently inspect the glass face at an angle under direct or strong natural light.

SAFE STORAGE

Because photographic emulsions are harbingers of mold, glass lantern slides should be stored in a cool, dry (climate-controlled) environment to prevent mold growth and moisture spotting on the image plates. Lantern slides and photographic glass plates should be stored vertically, for both ease of access (organization) and most critically, to prevent potential warpage of the glass due to pressure from stacking.

Acid-free, archival environments are generally not needed when it comes to the storage of glass lantern slides. This is because both the paper matting used between the glass plates as well as the original binding tape are almost always going to posses acidic properties. It is also true that protein-based emulsions (ie. silver gelatin) actually preserve better with age when exposed to a slightly acidic environment. Traditional antique glass lantern slide storage boxes like that pictured at right are still perhaps the most ideal (and aesthetically pleasing!) for safe and functional storage.

Glass lantern slide storage box illustration (circa. 1915)