Tag: digital projects

The Bancroft Pictorial Processing Unit is proud to announce that The Edward A. Rogers collection of Cardinell-Vincent Company and Panama-Pacific International Exposition Photographs has been organized, archivally housed, individually listed, and made (substantially) available online. This work was accomplished over two years, thanks to grant support from the National Endowment for the Humanities and, of course, careful hard work on the part of many library staff.

In this blog posting, Project Archivist Lori Hines describes some of the most challenging (and rewarding) work; preserving and providing access to fragile and often damaged glass negatives.

Handling Glass Plate Negatives: A Lesson in Mindfulness

The Rogers collection of Panama Pacific International Exposition photographs, received as a gift in 2014, includes over 2,000 glass negatives. These fragile items required special handling and archival containers with padding. Hardest to work with were approximately 150 oversize glass negatives ranging from 11 x 14 inches to 12 x 20 inches. Antique glass can become brittle and, of course, is heavy. From handling to wheeling the negatives back and forth to the conservation department and the digital lab, one had to be very conscious of every move and step taken.

This first photo shows how the negatives were received in the library. Note they have no padding between the plates and there are only original, brittle sleeves to protect them. A stack of ten or fifteen is very heavy and getting your fingers under one, to lift it off the stack, is challenging. The weight of the negatives on top of each other is also a risk — the antique glass can easily crack under the weight.

This photo shows how the negatives have been housed by library staff; vertically with corrugated archival cardboard around each. Our library conservators designed the housing to limit box weight, to provide protective padding, to protect the plates from abrasion as they’re removed, and to make handling safer.

The largest plates, at 12 x 20 inches, needed another housing solution because it was impractical to store them upright, but the weight of one on another was a concern. The Library’s Conservation Department built custom trays to hold each 12 x 20 negative, with just three plates (and their trays) in an archival box that is stored flat on a cabinet shelf.

The negatives are handled on the long side of the glass to offer best support and, during the cleaning, housing, and inventory process, are rested on a piece of thin foam padding to buffer any impact with the work table.

About 10% of the negatives arrived broken. To be digitized, we had to re-piece the broken negatives together on a supporting sheet of glass, like a puzzle, then hand it off immediately to the photographer in the Library’s Digital Imaging Lab. The glass sheet with the broken negative on top was then placed on a light table, so it was lit from behind, to be captured by the digital camera. The light table and camera are visible in the background of this image.

The results were often quite satisfying,  as can be seen in this example of a badly broken glass negative that was pieced together.

The finding aid describing and listing the entire Rogers collection, with more than 2,000 digital images, may be viewed at the Online Archive of California.

To browse examples of images scanned from broken plates, try searching the finding aid for “negative is broken”, and navigating through the results, or by browsing this Calisphere website search that retrieves just the broken-plate images.

Special thanks go to Christine Huhn and the staff of the Digital Imaging Lab; Hannah Tashjian, Erika Lindensmith, Martha Little, and Emily Ramos  of the Conservation Department; staff of the Library Systems Office and the California Digital Library that worked with us to get the material online; to Gawain Weaver Art Conservation (contractors for preservation and scanning of panoramic film negatives), and to the Bancroft Pictorial Unit team that devoted much or their 2016-2018 work life to this effort: Lori Hines, Lu Ann Sleeper, and a crew of student staff.