(The following is from the November/December 2016 Library of Congress Magazine, LCM, and was written by Phil Michel, digital project coordinator in the Library’s Prints and Photographs Division.)
A new, oversize scanner is putting the Library’s collection of panoramic photographs in focus.
One of the great joys in looking at a panoramic photograph is finding small details in a picture that can be several feet in length and show an entire city, or the whole crew of a battleship. It’s an experience that’s hard to reproduce in a smaller space, such as in a book or on a computer monitor or on a magazine page. But new viewing technologies let us zoom in and pan around to see the fascinating details, on computers and mobile devices. And new scanning technologies are helping the Library produce higher-quality digital images in a single exposure.
The Library’s Panoramic Photograph Collection contains more than 4,000 of these richly detailed photographs, most from the early 20th century, when panoramas were at the height of their popularity. They include cityscapes, landscapes and group portraits from all 50 states and several other countries.
They document the nation, its enterprises and its interests such as agricultural life; beauty contests; disasters; such engineering work as bridges, canals and dams; fairs and expositions; military and naval activities, especially during World War I; the oil industry; schools and college campuses; sports; and transportation. Ranging in length from 28 inches to six feet, the panoramic photographs were acquired when photographers submitted copies of their works to the U.S. Copyright Office in the Library of Congress for copyright protection.
The Library first began reproducing the panoramas in the 1990s by taking photographs of overlapping segments and then “stitching” the sections together to show the whole image on laser videodiscs in the Prints and Photographs Division Reading Room. Later, these copy photographs were converted to digital files and re-stitched to make them accessible on the Library’s website. The process was labor-intensive and the panoramas fit nicely on a screen, but it was difficult to see small features.
Now, with a recently acquired oversized flatbed scanner, the Library is capturing entire panoramas (up to 6-½ feet long) in a single pass exposure and at higher levels of resolution, so every little detail can be seen clearly. The Library relies on standard techniques that were developed with other government imaging experts to produce the best image possible. Using an image target with
wine fine lines and color patches, the Library can check the scanner for sharp focus and lighting balance and ensure that the colors are accurately reproduced in the scan.
You can read the November/December 2016 issue in its entirety here, along with issues from previous years.