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.
A view of some row houses on San Francisco's Nob Hill. The slide is titled "Nob Hill at Top of Mark", which I'm assuming means the Mark Hotel. Nice contrast in lighting. View full size.