Here's what a friendly law professor wrote (and he specifically checked for the superman image):
You check to see if the copyright was renewed. If it wasn’t then it is in the public domain. Took me about 10 seconds to find a document from the copyright office showing that no renewal exists for this copyright: https://archive.org/stream/Cop...
For all the films: see https://archive.org/details/Co...
Slashdot Mirror
Here's what a friendly law professor wrote (and he specifically checked for the superman image): You check to see if the copyright was renewed. If it wasn’t then it is in the public domain. Took me about 10 seconds to find a document from the copyright office showing that no renewal exists for this copyright: https://archive.org/stream/Cop... For all the films: see https://archive.org/details/Co...