Original caption: St. Louis, Mo. -- RECTIFYING A LUNAR PHOTO -- Mr. Ralph Wilson of the U.S. Air Force Aeronautical Chart and Information Center uses photographic equipment to rectify a composite of Lunar Orbiter Photos. Rectification is accomplished by tilting the composite on the easel until the crater and other features can be photographed at a predetermined angle. (U.S. Air Force Photo).
Keith Cowing: I found this photo on eBay. As you can see it was warped. So I used Photoshop to do a quick "rectification" so as to present the photo as it would have looked if it was laid flat. Back in the Lunar Orbiter days they did not have Photoshop - so they had to use this mechanical / optical process - one that had a clear military heritage.
Click on top image to enlarge.