A portrait is a record of a relationship

I always try to remember my own adage, and never tire of repeating it in every workshop I run, that a portrait is a record of my relationship with the person in the subject.

If the relationship is warm and trusting, it shows in the picture. If it's been grabbed on the run, like this shot of a pillion passenger on the chaotic bridge in central Agra, India, it looks grabbed on the run. And if you sneak up on someone, the picture will carry a slight voyeuristic quality. The best candids are those which combine the seeming contradictory qualities of the person being aware of you but at the same time ignoring you.

1. Wait and blend

One way to be seen yet ignored is to take the time to blend into the background. Imagine walking into a market in Kashgar in far western China: as a tourist, everyone notices you, especially if you arrive with a group. You represent new custom, a chance to sell their goods. But if you only want to grab some shots then run to the next sight, the anticipation turns to disappointment. Little wonder if some stall-holders are not too friendly.

What I do is find somewhere out of everyone's way and stand or sit for a few minutes. It doesn't take long before I become part of the scene. People say ‘Hello', I say ‘Hello' back. In ten minutes they start to ignore you, and you can start to photograph. People are less bothered by you because you have taken the trouble to spend some time with them, proven that you're harmless. That's how I obtained this portrait of an old patriach who at first wary but after 5 minutes was all smiles. And yes, he was in Kashgar Market.

2. Smaller the Camera, Smaller the Presence

For candids, compact and cell-phone cameras score over the big shooters by being unaggressive, non-threatening and almost friendly. If you haven't experienced it, have a friend point a big SLR camera with a big lens (complete with cavernous lenshood) at you: it's not a hugely cuddly experience. No doubt about it, small cameras are best for candid photography: that's why the Leica still does so well at photojournalism over all the bigger, better, faster cameras available. This, one of my favourite shots, was made with a Leica M6 in Western China.

3. Shoot from The Hip

The tell-tale sign that you're lining someone up to photograph them is putting the camera up to your eye. So if you don't want them to think that, leave the camera low. With their LCD screens, compact cameras are great for this. And some of the new SLRs now have live-view, which means you can view the image on the LCD screen on the back of the camera and not have to look through the viewfinder. It means you can carry on a conversation and even maintain eye-contact with your subject only minimally aware you're photographing them.

Hold the camera level (front/back and side-to-side). Use a wide-angle setting so you do not need to aim very precisely. Careful, though: this tends to produce a low point of view, so try pointing the camera upwards or else you will be looking up people's noses.

4. Looking away Distracts Attention

If you have ever felt that someone is watching you - and it's an uncomfortable feeling - you will understand that someone may pick up the sense that you're watching them intently, waiting for a photographic moment. If you're interested in this phenomenon, read this fascinating book by Rupert Sheldrake. Sheldrake's theory is that when we watch something we send out an attention wave of energy.

Anyway, where were we? Staring at someone with camera in hand is a dead give-away of what you're up to (attention waves or not). So you can practice a little deception: face away from your subject, but watch them from the corner of your eye. Mostly, however, I prefer to be open and honest when photographing. (Remember, the other meaning of 'candid' is about honesty and truthfulness.)

Wait Until They are Busy

Less of a deception but relying on a shift of attention away from you is simply to wait till your subject's attention is distracted by something else. Here it's handy to have a friend engage your subject in conversation. Keep sensitive, however, to your subject's feelings: if your presence with camera is making them nervous, then move away or wait until you can establish a trusting rapport. I have seen photographers exploit the fact that a stall-holder is busy having to serve customers and take snaps before they can be shooed away: but that really is to exploit the situation unfairly.

Share The Photos

Surely one of the biggest beauties of digital cameras is that you can share the picture with someone immediately you've shot it. So why not share it with your candid subject: if you've grabbed a shot and been noticed, immediately offer to show the person the shot. When they see you're not trying to hide anything, they are more than likely to cooperate for more shots. Of course, you lose that candid element. But that's only for a few minutes: if you encourage them to ignore you, they usually do so pretty quickly.

There's always a risk they will ask you to erase the image if they don't like it. If that happens, I never question or argue about it but erase it immediately. For me, it's important that my subjects are happy with how they feel: I owe it to them as a photographer.

The Picture is in their Hands

Sometimes people who are shy of having their face photographed may not mind if you photograph their hands. I love photographing hands myself, and often they tell you more about the person and what they do than the face does. You may have to work fast, though as people move their hands quickly, especially if they are at all nervous. Use the long end or middle of your zoom and shoot from 3ft (1 metre) or so to avoid projecting misshapen hands from a wide-angle view.