I met Julie Kertesz (or joyoflife, as she is known on Flickr) for a photowalk around the London Borough Market. I wanted to know how she manages to create such open and personal photographs of real people from the streets of London.

Her London Diversity collections have thousands of images. What's striking about them is not the sheer size and scope of the collections, but the way her photos seems to tell a story about the people in the images. A man takes a child for a talk. A woman sits and reads. A worker drives a truck. Two friends sit at a café table.

What was her secret? It's quite simple: she talks to them. "It's all in the body language," she told me. If you are open to them, show them that you are interested in them, they will be open to you. We were sitting over our first pot of tea in a small café. "I'll show you." And she called the waitress over. "May I take your picture?" The woman giggled. "Your face is so interesting. I would like to make a photo of you." She smiled. The woman hesitated. Julie asked a few friendly questions, and as they talked the woman relaxed. Julie took a photo. She showed it to the woman. "See, you are lovely."

As we walked around the market, we talked to people and took their pictures. It was hard to find a balance: to keep the conversation going and also take a good photograph. Most of the time, I was better at the interview than the picture. It felt like the first time I ran a usability test--a bit awkward. But it got better with practice. The better the connection I could make, the better the photograph was. It was something we created together.

My favorite photograph came near the end of the day. I had tickets to see to Waiting for Godot. A concessions stand in the lobby sold photographs and programs. The woman managing the stand was dressed in a black jacket with a black brimmed hat. She told me that she found the hat at a thrift store soon after she learned that Godot was coming to her theater and saved it until the play opened. She looked perfect for the play.

It's not a perfect photograph. But it will remind me of this person, and her story, and my day on a photo walk in London.

Julie's photos from the market and mine.