I downloaded a realism mod for Red Orestra 2 and when you are aren't directly looking though the sights you see a black ring! This was in the game but cut before the game released due to casual gamers. Is it real, I can't find anything about it because of how rare the old scopes are. Do actual old scopes work like that?
All scopes work like that. The easiest way to think of a rifle scope is as a tube with a magnifying lens in it - it's simply a telescope. If you don't look through a tube (like a telescope or microscope) in the correct parallel way, you see the dark ring with light passing through the lens. It's only by putting your eye in the correct focal path that the scope fills with the image of your target.