Thanks doktoratomik, but many people are surprised just how easy it is to make a copy of a photo with just one button press, doesn't matter if its flash or anything else used. If it appears on the screen with no copyright its very vulnerable to exploitation. I say exploitation because I'm not against someone using a photo for educational or illustrative purposes if I'm informed but using something to avoid paying for a professionally produced image damages many peoples chances of making a living from photography.