A、Because he often forgets to tell the people he is taking pictures of them. B、Because he prefers to portray people who are not

W: I like that picture that you put up on the wall yesterday.
M: Oh, thank you. It’s a photograph that I took on my vacation last year.
W: You took it yourself? I didn’t know you were a photographer.
M: Oh, yes, I’ve been taking pictures for years.
W: It sounds like an interesting hobby. DO you have any more of your pictures here? May I see them?
M: Yes, certainly. I haven’t really sorted them out yet. Some of them are faces, just faces of people whom I see when I’m walking around.
W: Do you let them know that you’re taking pictures of theme
M: I try not to. I don’t like pictures of people who pose for the cam- era. I like people who are going about their daily business with- out being aware of the camera.
W: And what are the rest of the pictures?
M: A few of them are landscapes, and the rest of them are still-life studies that I took in my studio.
W: Oh, you have your own studio! But I suppose you need a lot of equipment. How many cameras do you have?
M: Well, I have several, but I use two of them more than the others.