I don't even know what to call this problem, so if there's a thread about it already please point me in the right direction. I recently filmed a boat cruise down a river, and as we pass a bridge with railings flashes of colour appear between the railings. The same happens on the sides of some brightly lit houses, and to a lesser effect some sparkles on the water.

I had a polarising filter on the camera, but have noticed this without the filter also.

Could someone please tell me the technical term for it so I can look at it not happening again, or how to remove it from my videos? Or if it has been posted about a link to it as I've no idea what it's called.

Thanks for any help.