There have been many things that scientists have predicted, but been unable to confirm without a photo. For example, the existence of black holes was long theorized, but until one was caught on camera, they couldn't know for sure. Even Einstein doubted their existence, instead believing that it could be a phenomena we just didn't yet understand. 

But for every one of those, there are dozens of other things that scientists could never have conceived of until one of them stumbled into their lap. The Elbow Squid comes to mind, along with a hoard of other odd deep sea creatures. We probably don't even know about the vast majority of deep sea life, and won't until we catch it on camera. 

Legends like the giant squid and rogue waves were long talked about by experienced sailors, but it took actual filmed events for the rest of the world to believe in such legends. Even the giant sequoia tree was thought so massive when described by early European explorers that many people thought it a gross exaggeration. Here are 20 things that nobody believed or would have thought existed, had we not caught them on camera.