I usually know when I take the picture. There's always some kind of un-self-conscious thing going on, so that it doesn't look like they're there for the sake of having their portrait taken.

Can you see the deaths, divorces, job losses or changes, disappointments, surprises, and successes on people's faces? Have they been happy, sad, disillusioned, or gratified? I have been trying the single, vertically shot portrait with my 8 x 10 since 1985 and never felt I succeeded in finding what I was looking for.

The idea of the portrait itself is my great love. The questions and answers in it can go on forever and ever. It is what happens in the eyes or with a tilt of the head. I keep going because it's too interesting to stop.

[My advice to a beginning photographer is] sit down with a pencil and paper and think about what your life is about. What you are about. Don't even take a camera into your hands before you figure that out.

Shooting great-grandchildren of some of the people I had photographed in the past, who are around the age of 15, is fascinating to me, because they're right on this fine line between still being children and starting to become themselves.

I know now that before I take a picture I have to be sure about how I feel about the subjects. What I don't know is if I should explain to them what I'm doing while I'm photographing them.

I never thought that my work was going to become well-known. It started happening slowly, without my realizing it. But when I did, it was terrifying. I still can't believe that people let me photograph them. The trust is amazing. But I've always put them in a context that is dignified, and that's really important.