Director or Cinematographer lens?

[Kentertainment]

I have a basic question, and using a billion descriptive words in Google isn't helping me either.

I basically want to know what the lens is called that directors and cinematographers often carry with them. They look through it when planning a shot just to see how it'll look before setting up the camera. Usually you can adjust the aspect ratio in the lens too.

Thanks!

 

[Kentertainment]

Okay, nevermind. I found out it is called a "Director Viewfinder." Now... does anybody know any good ones for relatively cheap. I'd say in the $100-$200 range?