The key to improving your outdoor portraits is knowing when it’s the right time to use flash. Start by looking at the existing light falling on your subject and evaluating the range of shadows and highlights appearing within the scene. Learning to see light is not difficult but takes practice and using the cameras LCD preview screen will help you analyze your outdoor flash photographs to see if your efforts are successful. My guess is that with a little experience your answer about when to use flash outdoors will be “most of the time.”
A soft light source is a better choice for portrait and glamour photographs because it’s more flattering to the subject and, as a side benefit, requires less retouching. One of the best bargains for improving on-camera flash photographs is a Sto-Fen Omni Bounce flash diffuser. It’s available to fit different flash unit from many different manufacturers. The flash diffuser easily slips on the front of the flash and produces a diffused “bare bulb” look that softens shadows and reduces the harsh effect of direct flash. It’s compact and easy to use in either direct or bounce mode and is the simplest, easiest way to improve the quality of your flash photographs—indoors or outdoors—without taking the flash off the camera.
When there’s plenty of ambient light as your main light source, the best way to use your on-camera flash is as fill. This helps separates your subject from the background and focuses the viewer’s attention on the subject. In fact, when you have too much ambient light using flash lets you control contrast and add dimension to the photograph. Andria was photographed with a Canon EOS 60D and EF 28-135mm f/3.5-5.6 lens. Exposure was 1/200 sec at f/3.5 and ISO 200. To soften the light from the speedlight I attached a Sto-Fen Omni Bounce diffuser