Marcus Hawkins
There may be plenty of light on a sunny day, but adding more can give you better results
Marcus makes using flash in daylight a piece of proverbial by explaining how to match your exposures.
Aburst of flash might be the only way to record images in the dark, but a flashgun really shines when adding an edge to shots taken in broad daylight. Sunlight creates high-contrast pictures, filled with bright hotspots and dense shadows. The dynamic range is too wide for the camera to capture in a single exposure, so you have to choose to record details in the shadows and lose detail in the bright areas, or vice versa.
To reduce contrast, you could shoot in the shade, use a reflector to bounce light into dark areas, or try HDR, none of which may be practical. Or you could use a flashgun. Using flash in daylight means dealing with two light sources, and it’s simpler to treat them separately, with either the sun as the main light and flash as a fill light, or flash as the main light that overpowers the sun.
To use flash as the fill light, set an exposure for the ambient light so that bright areas aren’t overexposed. Then activate the flashgun’s E-TTL mode and let the camera work out how much light is required to lift the shadows (or do it yourself in Manual flash mode).
Making the flash overpower the sun requires a lot of power. Working in Manual mode, set the camera’s fastest flash sync speed and dial through the available apertures until the background is underexposed. Now switch on the flash unit and adjust its power to taste.