My client told me that I need a special filter for a camera for shooting a green screen. What is he talking about?

I'm at a loss to know unless it is a special situation you are shooing under. I shoot green screen regularly with nothing special on the camera.

If you get more info about what this mysterious filter is be sure to let us know.

Some people put green gels on their background LIGHTS to make the green more pure, maybe he's confused...have never ever seen any reference to a filter on the LENS.....just musing, maybe if you had a glare on a background a polarizing filter on the lens might help to remove it, never have tried this or seen any mention of doing it, however.....