I currently am in Singapore for an exchange year. The architecture here is impressive, the lights at night are wonderful, but what I find to be the most interesting are the people. You can find people from all races, sizes and ages here.
I would love to just ask some of them on the street, in the bus, in the MRT stations or in the malls if I could take a photo of them. However, I guess, a little preparation can't hurt as I'm not too experienced with portrait photography - especially with the lighting.
Can you give me some tips on how to light spontaneous portraits? This means I can't put up a studio environment and don't have much time to adjust the lights. Furthermore, I'll have to deal with an array of different lighting situations (outside, sunny, cloudy, at night, in a mall, etc). Last but not least, I don't want to scare people away with huge amounts of equipment!
Should I buy a flash, and if yes, which one?
Of course other tips on both interaction with people and the technical side are welcome, too.
PS: My equipment is a Canon EOS 450D + EF-s 60mm / f2.8