Most of the photos on this site were extracted from reference images (high-resolution tiffs, 20 to 200 megabytes in size) from the Library of Congress research archive. (To query the database click here.) Many were digitized by LOC contractors using a Sinar studio back. They are adjusted by your webmaster for contrast and color in Photoshop before being downsized and turned into the jpegs you see here.
On the left: "Full Current: Young woman using an electric device for massage and stimulation of her face and neck." On the right: "Chest Developer: Woman at dressing table holding electric vibrating machine against her chest." Royal Specialty Company, Cleveland, 1909. Library of Congress copyright deposit, series of five 8x10 photographs: "Chest Developer," "Full Current," "Feels Good," "I Always Use It," "Smoothing the Wrinkles." View full size.
The photos you see here on Shorpy are not just resized versions of the images found in the Library of Congress archives -- they are extracted from the LOC's full-resolution reference tiffs: a process that generally takes anywhere from half an hour to several hours per monochrome image, depending on the amount of work that needs to be done to bring detail out of the shadows, suppress overexposed highlights, and remove blemishes caused by dust, scratches and mold. Color images require correction for color cast as well. The before-and-after composite above shows the condition of some of these old glass negatives a century after they were exposed, and how they look after a day at the digital restoration spa. This one is from 1908. View full size. Below is the 36 mb archival tiff resized to 512 px wide. The restored version is here.
Below is another before-and-after example. Restored version.
Below: Another monochrome example. Click to enlarge.
April 1942. "Aircraft construction class. The flame of welding torches has replaced the soft lights of a nightclub in Daytona Beach, which has been taken over for a vocational school to train war workers for Florida's pooling program. Pictured above is instructor C.C. Gravelge showing one of his classes the difficult art of overhead welding in preparation for their initiation into aircraft welding jobs on the De Land pool's war contract." View full size. Medium format safety negative by Howard Hollem for the Office of War Information.