Hi. I would like to buy a reflector. I shoot kids (not very well yet, but improving). I mostly shoot them on the fly as they play, at parties, etc. but occasionally I find a nice little well lit nook by a tree, etc and think a reflector might be helpful. When I was looking on B&H I see that there are about a trillion different kinds and sizes. I want one that is portable (I suppose that means collapsible) and not too big..unless someone thinks otherwise. Any advice on size, brand, shape, color, etc? Thanks so much.