answer: #Person2# tries not to let people know #Person2# is taking pictures of them because #Person2# likes people who are doing their business without noticing the camera.
documents: #Person1#: I like that picture you put up on the wall yesterday.
  #Person2#: Thank you. It's a photo that I took on my vacation last year.
  #Person1#: You took it yourself?
  #Person2#: I've been taking pictures for years.
  #Person1#: Sounds interesting. Can I see some more of your pictures?
  #Person2#: Yes, certainly. Some of them are just faces of people who interest me.
  #Person1#: Do you let them know that you're taking pictures of them?
  #Person2#: I try not to. I like people who are going about their business without knowing the camera is there.
  #Person1#: I suppose you need a lot of equipment.
  #Person2#: Well, I have a dozen cameras, but I use two of them more than the others.