Many photographers do not even think to use flash outside, preferring to use 'natural' light. Others prefer to use reflectors to bounce light on to their subjects. My motto is "if I can light it, I will".
Using small camera flashes outdoors - especially in the Florida sunshine - can be problematic. High ambient light levels mean that small apertures and low ISO values are necessary to get a shutter speed low enough to synchronize with the flashes. Many modern digital SLR cameras support a high-speed synch flash mode, but the trade-off is greatly reduced flash power.
The key to interesting flash photographs is blending the ambient light with the flash light. One way to do this is to set the camera in manual exposure mode, and meter for the ambient light. Select the lowest aperture and ISO that will give you a shutter speed that will synchronize with the flash (in my case, this was 1/250 second at f/14 and ISO 200). In our shoot yesterday (more images below this post) I wanted to reproduce the beautiful blue sky, so I metered on that and slightly underexposed it. Here's the resultant shot:
OK, the sky looks good, but since I have the model (Robyn) in relative shade, she is significantly underexposed in this image. Not to worry, now we can add flash light to the scene to illuminate our subject.
For this shot, I used three Nikon SB800 Speedlights mounted on a lightstand about 6 feet away from Robyn at camera right. The flashes were triggered with a Pocketwizard radio trigger. The Speedlights were all in manual mode and set at 1/2 power. The flash power output was adjusted and chosen to match my chosen aperture (f/14). Here is the shot:
The images were both shot with a Nikon D3 and 14-24 mm lens at 14 mm. Why three lights? Well, firstly, one light may not have produced enough power to match the strong ambient light levels. Secondly, using multiple lights mean that each one has to work less hard and therefore recycle times are quicker (less time waiting between shots). This was important yesterday as we had three photographers shooting with the same lights.This is a simple technique once you have it down, and can usually be relied upon to produce striking images.