Some advice from you experts please....If you're indoors taking photos where there isnt enough ambient light without flash, what settings do you use on the camera/flash? I'm confused. if I use Av/Tv, the camera uses the same settings whether external flash is on or not. eg. With Av mode, the shutter speed will be too low (1/15). So what mode do I use? Av / Tv / P ? what settings for camera and flash? Point flash up / 45 degrees / direct ? Please give some examples of how you professionals work. I will be using canon 10D, 420ex and 28-75mm 2.8 lens.