If you go to the camera_free.xtbl you can modify the view angle of the DFA attack.
I bolded and underlined the values that change how high or low you can look. -90 is straight down, 90 is straight up.
From my own experience, you can't actually charge as high as you can look - if your target is outside a certain distance, you can't seem to trigger it. I've tried with the abduction gun a few times to get as high as I can, but while you can 'reach' much higher with your actual vision, it can't trigger all the way that you can see.