I love the title of this image: No way back! The street sign makes that point. Yes, sometimes flash outside is the thing to use. This coming from a lover of reflective, subtractive, tungsten, HMI, etc.– what you see is what you get lighting. On this get away image I wanted some feeling of the movement, but still wanted to get the bride tack sharp. Solution: 1/30 sec. and FLASH! She is in so much darkness that my f.2.8 exposure at 400 ISO of the exciting street light outside the car doesn't effect her. Then comes the flash firing at her at around 1/5000 of a sec or however short the flash lasts? Keeping her in darkness keeps her sharp while the rest of the image blurs. PS. Camera, Canon 1d (2003) Lens Canon 20-35mm f 2.8 at 35mm.