Some believe they are real, some don't. It depends on what you think.

If they isn't any hard evidence, who's to say that they aren't real or not?

Inferences in the eye may smudge your eyesight, and you get what people believe as ghosts.

Pictures in a camera aren't to be trusted either, it's easy enough with photoshop and light tricks.

Video footage? No. A video can be edited as well.

As of current I am not sure, only because, everyone else from childhood has told me they don't or they do. But I can be wrong. Maybe they do exist. And maybe they don't. How am I supposed to know?