One of the most fundamental skills every portrait photographer should learn is using flash for lighting their images. However, flash is not just for working in a studio. This helpful video tutorial will show you how to use flash for outdoor portrait photography.
Coming to you from Jiggie Alejandrino, this great video tutorial will show you the ins and outs of using flash for outdoor portrait photography. Even though there is often an abundant amount of natural light already available outside, sometimes, we want to add more light to either augment the natural light or to better shape it to our creative vision. For example, one of the most classic outdoor portrait looks is a single subject or couple with the setting sun behind them. The problem is that in order to avoid blowing out the sky, you need to dial in exposure settings that will leave your subject(s) in shadow. To remedy this, portrait photographers will add a flash to bring the exposure of their subject(s) back to the proper level. This is just one example of how artificial light is used outside, however, so check out the video above for the full rundown from Alejandrino.
I'm not sure learning to shooting flash with daylight on aperture priority is a good idea. Firstly do not use auto iso (this will really screw with your head) shoot in manual, adjust setting to get ambient light correct or under exposed, then turn on your flash and turn up or down your flash to get the fill right. Adjust your shutter speed to change ambient lighting look. Do not change you ISO unless you run out of flash power, if so start again. The flash element is only effected by aperture and ISO (unless you go beyond flash sync speed) You will learn a lot more by starting off in manual...