If someone's incredibly sad, then no amount of photography can make them happy. A portrait painter is not bound by realism. I can choose what to put in the frame, change the dynamics, add a symbol like an open door and arrange the individual so she's looking out towards it. There are ways of hinting at deeper aspects of a person's life.

You often understand a subject's state of mind only in the aftermath. I'm so engrossed in painting, in the actual process, it's only when I take a step back I see whether I've got them right and also something of their own aura.

Not everyone's open. Some subjects are closed and won't want to say anything; some know exactly how they want to portray themselves. Some see a portrait as a pure projection of self-image, a mask or veneer, instead of a deep psychological unfolding.

I'm quite euphoric when I'm working. It is a complete immersion. I don't work that well when I'm upset. My work is quite controlled. If I'm not really together, I'm not going to do well, which means no noise. I used to play music, but it's a distraction. I have two children, age five and three, but I work when they're not here.

The subjects of portraits are not expected to look happy. No one really smiles. There's certainly no teeth. I'm working on seeing if it's acceptable to make figures happier. One problem is the British have always been suspicious of people smiling. Maybe people don't quite trust it. It's a fine line for any portrait artist.