Naked Science Forum

Non Life Sciences => Technology => Topic started by: melaniejs on 12/03/2020 16:30:20

Title: Why are rain spots on the TV camera lens in hexagonal shape?
Post by: melaniejs on 12/03/2020 16:30:20

Richard asks:

Why are rain spots on the TV camera lens in hexagonal shape (from televised sports events). I would have expected round spots!

Anyone here knows?

Title: Re: Why are rain spots on the TV camera lens in hexagonal shape?
Post by: Colin2B on 12/03/2020 16:56:15

Inside the lens is a variable diaphragm which controls the amount of light entering the camera. This diaphragm usually consists of 6 leaves making a hexagonal hole. Anything on the lens surface is out of focus but will take on this 6 sided shape. You might also see it in out of focus lights in the background of a shot.
It also happens when bright light hits the lens surface and is reflected around the elements of the lens, in this case you might see a whole series of lights in a line - called lens flare.