Walking round my city, the camera is often hanging from my neck. I love watching people and am constantly seeing facial expressions and natural actions that exist only for seconds or less and would make wonderful photographs. People behave differently when they know they`re being watched but I`m not sure if I should feel bad about translating people-watching into voyeuristic photography. I very rarely take the shots as a result, not wanting to feel rude or intrusive. Can anyone offer any tips on capturing these moments? When you see a fleeting scene do you just shoot away? Do you get right back and use a tele? Do you ask permission first (if at all) and then hope your subjects will return to acting naturally and recreate the magic?