If fill was used here, you didnt underexpose the ambient enough to make the fill apparent and to control the sky. You usually want to underexpose the background by 1.5 to 2 stops to saturate the background and use the flash to highlight your subject. Obviously thats done to taste so your mileage may vary.
I see what you mean. I am just wandering that if I maintained my shallow DoF and just increased the shutter speed, would I be asking too much of my flash at HSS mode?


