Shooting on location in the middle of the day can make controlling the sunlight very difficult. I have chosen my canon 5D mk iii. So if I want to shoot with flash off camera to control the bright sun I’m limited to a x sync of 1/200 of a second. This is going to make my aperture F16 and that is too much depth of field for my preference. I don’t like to use ND filters to open up my aperture because they make it difficult to see through the camera. I could use high-speed sync but this technique is flawed by the fact that the flash is at its lowest power as it pulses across the chip. Also, it would never give me enough power to overpower the sun in the middle of the day, so I only use this technique on cloudy days.