I use my head a lot.
No, really. If you rest the camera up on your shoulder, it's very hard to spot from about 270 degrees of looking at you, and you can see clearly while doing it. If you keep your eyes moving, someone's unlikely to spot the camera before you spot them.
My way isn't what you'd call 'stealth,' I just like to be the first one to know when there's a shot happening.
Behind the thigh also works pretty well, or just holding the camera low in general. The object isn't really to 'hide' the camera, it's for the camera *not to be seen.* These are different things.
One way for the camera not to be seen is for you to not disrupt the flow of foot traffic, too, so it's about where to walk, when to stand, and otherwise not draw attention in the first place. What people are really likely to notice is 'Why is that person just standing there' ...then they see the camera.
If you keep moving, keep that bag moving behind you, too, (this is also good for general gear security if there's worry about anyone trying to lift stuff off you, standing there looking distracted by fancy camera is a big flashing light over your head in more ways than one) and most of all keep your eyes moving: previsualize, know your light and settings and where you're going with compositions before you even put the camera to eye, (I always like a hand meter on the street, take my readings while walking. If you have a camera with a top LCD, you can also wave that and get your readings without presenting the camera that way, an obvious thing it took me a while to clue into.
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(BTW, nice post, there, Javier.
The confidence thing is pretty key. People take their cues from each other in many ways: the surest way to make someone uncomfortable with what you're doing is for *you* to look uncomfortable with what you're doing. (And let me tell you, bad arthritis days really cramp my style. Hard to look comfortable with *anything,* never mind do my usual schmoozing. I generally don't like to hide, I prefer to interact.
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