Using OCF outdoors isn’t as complicated as you might think. It’s also tremendously more beneficial than most newcomers believe. I use OCF for just about everything I shoot. If you’re intimidated by using it outside start with this simple guidance:
You want to look at your images as though they are two images combined into one. The first image that you’re going to create is strictly based on camera settings. So you’re going to set your camera so that everything in the background is exposed the way you want it. Look at it as though you were shooting a landscape or an environmental image of just what’s going on in the background. Use your aperture, ISO and shutter speed to get that looking the way you want it. Once you’ve done that, don’t make any more changes to the camera. Turn on your flash and add flash to your subject. A great place to start is 1/8 power. That’s about the middle of everything and take a picture. If it’s too bright you’ll adjust your power down to expose your subject properly or, if it’s too dark, you’ll turn the power up to put more light on your subject. A gray card is the tool I recommend to make setting exposure easier. But, you could use a light meter , like a lot of people, you could simply eyeball it based on what your screen shows you on the back of your camera. There are no magic settings, this is just a starting point and you have to adjust from there. But again, once you have your background set the way that you want it with your camera settings, don’t change them. At that point all you should change is the power of the flash.
Get out there and try it! That’s the most important part!