Daylight Flash

By: Adah Walker

Daylight Flash

DICK GILCREAST

Bright sunlight can be pretty harsh for photographing people, particularly when it is high in the sky causing shadows under the eyes. The use of flash in bright sunlight may seem like overkill, but it sometimes helps to fill those shadows. Often called "synchro-sun" flash, it consists of approximately matching the intensity of the sun with the light of a flash to fill chin, nose, hat brim and eye shadows.

The usual method is to determine the exposure in daylight with the shutter speed set no higher than the synch speed of the camera. For ISO 200 this would be about 1/250th at f/11 or 16. Set the flash for auto-exposure at f/11 or 16 and shoot within the distance range the flash unit recommends. This is a good papparazzi exposure to use in all kinds of lighting, day or night.

However from a pictorial standpoint, pictures of people will look better with the sun behind them. This angle avoids most eye and hat shadow problems, and some fill flash will provide catchlights in the eyes, and correct the color temperature of light from blue sky.

For work with flash the Leica M cameras offer the twin advantages of being able to see any unwanted subject motion in the viewfinder during the exposure, and seeing whether the flash fired. If there is a blink or motion or no flash during the exposure you can reshoot immediately. A reflex camera’s blackout during exposure will miss these problems.

But, on the down side, Leica M film cameras are limited to 1/50th synch speed with electronic flash. This can be a problem for flash work in bright sun, especially at high ISOs. However when we move around to the shadowed side it is less of a problem. Even in brightest sun, the exposure on the shadow side of a person at ISO 200 is no more than 1/50th at f/11. So with auto-flash set at f/11 -- distance range between 2 and 15 feet with a typical unit -- the flash will equal the shadow exposure, adding eye catchlights, helping to fill any shadows, and correcting color temperature. Synchro-sun photos of people made from the shadow side are usually more attractive than from the bright side, with better modeling of faces, less squinting, and the background will remain relatively bright which helps to concentrate attention on the subjects.

Exposure for the illustration made with an M6 on ISO 200 color neg film was 1/50th at f/5.6 using a weak auto-flash set at f/5.6 in the shadow of the tree. Auto-flash using f/11 would also have been possible here, but the comparatively strong flash would have overpowered the scene, making shadows of its own on the tree, and darkening the background. At f/5.6 the faces and the background are all within a more natural looking brightness range.

Even with an M camera if is possible to work from the brightly lit side if necessary, but it involves changing to a slower film or ISO to avoid overexposure. At ISO 50 the bright sun exposure is approximately 1/50th at f/11 to f/16. Cameras with higher synch speeds such as an R camera or an M8 can of course manage bright side exposures at faster ISOs. With an automatic-exposure flash unit on the camera just meter the daylight exposure, determine the aperture at the maximum synch speed, find the flash range for that aperture, and shoot within those distances. But give me a nice tree shadow any day for a daylight flash photo that doesn’t look like flash.