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Library of Congress Makes Master Scans Available Online |
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A new, greater level of detail is now instantly available from the Civil War photographic negatives at the Library of Congress now that the Prints and Photographs Division have posted their highest resolution scans online for immediate, free downloading.
“The super high-res files for the Civil War and Brady-Handy collections went live this afternoon. Have fun!” Curator of Photographs Carol Johnson advised by e-mail on Jan. 12.
That means the library’s master archival digital scans of the more than 5,000 negatives in the Civil War photographs collection and the more than 5,000 negatives in the Brady-Handy Collection are now available instantly. They were previously available only by special request or by visiting the P&P Reading Room in Washington, D.C.
The 5,000 Civil War negatives consist of Alexander Gardner’s large plate and stereoscopic negatives, the more than 1,000 negatives in the E. & H.T. Anthony & Co. “Photographic History – War for the Union” stereoscopic series and a vast array of studio portraits. The Brady-Handy collection consists mostly of early postwar studio portraits.
There are now three levels of detail available online for the images in these vast collections: low resolution JPG files, high resolution TIFF files and the new “highest resolution” TIFF files.
A typical 3x3 inch negative from the Anthony War for the Union series, previously available online in a high resolution TIFF file of about 25 MB, is now also available in a file of more than 90 MB. A typical 4x10 inch Gardner stereo negative, previously available as a 10MB TIFF file, is now available at more than 40MB.
The higher resolution files allow researchers to intimately examine the scenes in these large, detail-filled glass plate negatives.
The pixels-per-inch of each negative varies, said Phil Michel, digital conversion coordinator for the P&P division. “It depends on the size of the original negative,” he said in an e-mail. “We set our specs at that time to produce an output of 7,500 pixels in the long dimension. So for an 8x10” original, for example, the scan was produced at ~750 ppi.”
The high-res scans for both collections take up almost 1,100 GB of Library of Congress server space, he said.
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