[Arkady]

First of all, the copyright expiry period for images/graphics, varies from country to country. Secondly, in most countries including the UK it's seventy years not fifty years (fifty years for music.) And lastly just to pick up on a common misconception, there is no such thing as a non-copyright image unless the copyright has expired. What does happen if copyright holder wishes to make an image freely available is, they will publish it with some kind of rights issue license. It may seem to be essentially the same thing, but this is in fact an important distinction, and you should always check the limitations of the rights issue before deciding to use an image.

p.s. Again in most countries; the expiry period commences after the author has died.