I recently stumbled across the Flickr Commons. An area on the vast, and ever-growing library of imagery within Flickr, that represents the visual archives of many cultural, heritage, and library institutions around the world. Some of these institutions include: Getty Research Institute, NASA, The Library of Congress, Getty Research Institute, The National Archives UK (which is where all of the above images came from), and The U.S. National Archives.
There's a full list here, and a visual list below:
What's interesting and exciting about them, is the usage category they all fall into: "No known copyright restrictions."
For someone like myself, who is constantly seeking out unusual imagery (particularly archival imagery) this usage category is very interesting and exciting. These days, much of the world's archives are either inaccessible, or held by big corporate image banks like Getty Images or Corbis, and are expensive to use.
Reading further, about into the meaning of "No known copyright restrictions", I gather it doesn't actually imply we can use these images carte blanche, but simply that no one really knows who may (or may not) own a copyright on the images.. it's "unknown". And trying to determine if they are actually owned sounds like a rather difficult undertaking.
Here's the explanation they provide:
Under "The Commons," cultural institutions that have reasonably concluded that a photograph is free of copyright restrictions are invited to share such photograph under their new usage guideline called "no known copyright restrictions."
Photographs can be difficult to analyze under copyright law, not only because laws around the world differ with respect to scope and duration of protection, but because the photographs themselves often lack credit lines, dates and other identifying information. Libraries, museums and other cultural institutions have a great deal of experience with photographs because they frequently collect, preserve, document and study them in accordance with their nonprofit missions. However, in many instances, a cultural institution will not be the rights holder under copyright law. Therefore, it can neither grant permission to others who wish to use a photograph nor provide a guarantee that the photograph is in the public domain
The images in the Flickr Commons cover every conceivable subject matter and take all sorts of forms, from maps, photos, letters, declassified documents, posters, artwork... I even found Jane Austen's last will and testament! My only complaint would be image size. The images are only 500px to 1000px wide in size. So not really large enough to appreciate any detail at all.
So what are they for? If they are there for us all to admire and study, why not make them large enough for us to admire and study? They certainly aren't large enough for any print or video usage either, and perhaps that's the reason they are small. To protect them from unauthorized usage... even if they they have"no known copyright restrictions"
At any rate, spend some time in the Flickr Commons. It's an incredibly deep resource for historical imagery. You won't be disappointed, but be warned - it's addictive!
List of Flickr Commons participating instutions: