Category Archives: Photography

Hebrew and Judaica Manuscripts Project

Tefilot u-piyuṭim : le-ben Pesaḥ le-ʻAtseret aḥar ha-pereḳ תפלות ופיוטים לבין פסח לעצרת אחר הפרק. [כת”י] (Rare Book and Manuscript Library, Columbia University)

Between 2014 – 2015 at the behest of Michelle Chesner, Norman E. Alexander Librarian for Jewish Studies, PDCD staff completed a project to make a number of previously photographed Hebrew and Judaica Manuscripts fully accessible to the world on the Internet Archive. Here is some background from Michelle:

Ketubah : Venice, 1673 (Rare Book & Manuscript Library, Columbia University)

“Columbia’s Hebrew manuscript collection is one of the largest in the country, behind only the Jewish Theological Seminary and Hebrew Union College. It was, however, unknown by many due to a lack of cataloging and exposure until recently.  After a generous donation from the Norman E. Alexander Foundation endowed funds for Judaica in the libraries in 2010, CUL was able to catalog nearly all of the manuscripts in the first step toward accessibility.  The next step was an exhibit of the manuscripts in 2012 – 2013.  A partnership with the National Library of Israel yielded digitized images for many of the manuscripts that had been previously unrecorded, and they became accessible via the NLI’s Institute for Microfilmed Hebrew Manuscripts and their new Ktiv interface for digitized Hebrew manuscripts.  Posting the images to the Internet Archive allowed us to create a space to highlight the manuscripts at Columbia (the NLI sites contain manuscripts from all over the world) and it has become a place to point to for a sampling of our extensive collection.” — Michelle Chesner

 

Ketubah Damascus, 1830 (Rare Book & Manuscript Library, Columbia University)

In PDCD, we worked from Michelle’s detailed spreadsheets to derive new catalog records for the electronic versions of the materials. We then used Photoshop to crop and deskew them and uploaded them in large batches into their own special subcollection on Internet Archive. We also updated all the records in OCLC and Voyager so that the materials will be findable both as objects on Internet Archive, but also through OCLC First Search, the international bibliographic database.

There are now 244 titles in this very rich collection, containing numerous ketubot (marriage contracts), Torahs, books on poetry, fairy tales, astronomy and numerous other topics. Many are brightly illustrated, like the ones featured in this post.

Here is a link to the full collection on Internet Archive: https://archive.org/details/culhebrewmss

The Complexity of Color – Creating Digital Surrogates

Researchers and students today have an increasing expectation of being able to find needed materials and information online. Libraries and other cultural heritage institutions have responded by focusing on digitization for both preservation and access to these cultural heritage materials. The Digital Imaging Lab, as part of the Preservation and Digital Conversion Division, is at the center of the creation of digital surrogates for preservation and online access at Columbia University.

Digital surrogates are “faithful” reproductions of an object at the time it is photographed. It is an accurate record of the item’s appearance and condition at a singular point in time. Since we want to handle the material as little as possible, a use-neutral file is created that is large enough to cover the many expected uses of an image file, from viewing on a computer monitor to reproduction in books and journals. But how do we know what is large enough? Back in 2010, in order to ensure a certain level of quality, federal agencies set about writing a set best practices for all those involved with the creation of digital surrogates for the federal government. This became known as The Federal Agencies Digitization Guidelines Initiative or FADGI. These guidelines became the standard for cultural heritage institutions here in America. European institutions adopted similar standards, known as Metamorfoze. In the Digital Imaging Lab we strive to reach the 3 and 4 star ratings parameters set forth in these guidelines (page 10 of the FADGI guidelines has an explanation of the star rating system).

Creating a digital surrogate.

Creating a digital surrogate. Photo credit: David Ortiz.

By far the biggest challenge faced by any institution in the creation of digital surrogates is the capture of accurate color. Color is a highly complex subject. It is thought that the perception of color takes place in the mind as an endpoint of a sequence of physical, physiological and psychological events. Each individual perceives color in his or her own unique way. Just like individuals, every device used in our lab, from the monitors we use to the cameras to the printers, capture and display color differently. Luckily scientists have been studying color for a long time and there exist several models for the mathematical description of color. In the digital realm we use a color model called RGB, named for the red, green and blue light that devices use in capturing and displaying color. Certain amounts of each of these lights (on a scale of 0 to 255) will produce almost all of the colors we can perceive.

Before we can use any device in the Digital Imaging Lab we must first find out how that device captures or displays color, and then, using software, we can bring it to a known state of color capture or display. The process in a nutshell is this:  using scientifically created and widely recognized color targets that have patches of mathematically defined colors, we have the device capture an image of the target (or for a monitor, display a set of defined colors). We note how far off the device is and then create a set of offsets (or corrections) for the device. These offsets are what are typically called color profiles.

This is a very simplified version of what goes into color profiles. The color of the walls, ambient lighting, the position and type of lights being used for photography, all have unique characteristics that must be dealt with when getting ready to create a digital surrogate. Even the pigments in the object being imaged can affect the sensor in unique and surprising ways. Contrary to the wishes of most cultural heritage institutions, creating high quality digital surrogates that have a good chance of persisting long into the future, is never as simple as pushing a button.

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Digital Surrogate of a page from a medieval manuscript, at bottom is a Kodak color target.