I went out Monday evening looking for a photo opportunity on Union Square.  There was enough breeze in the air to make the flags dance in the wind, but there was no light on the flags at all.  I decided to try my 550ex flash in Multi mode to get a multiple exposure effect on a single image.  I set my camera up at 1″, f/4, and ISO 400, and then set the flash to strobe 5 times during that exposure to create this effect…