Make Light Like Sunshine for Macro Photographs
Perhaps the most complex of all natural lighting techniques is creating direct sun on a cloudy day. You need a battery-powered flash or a strobe to make this happen. (Use either, depending on which you prefer.)
The photograph shows a subject taken on a cloudy day to look as though it was basking in the sun. It looks realistic because the photographer took various steps to emulate natural light.
50mm, 1/160, f/11, 400
When you want to mimic the sun with artificial light, keep in mind the following points to ensure that the light is flattering for your subject and appears realistic:
Avoid on-camera flash. This style of light doesn’t really happen in nature, and it provides flat, boring results. Instead, keep your flash separate from your camera and sync it by connecting camera and flash with a sync-cord or transceivers.
Consider the direction of your light. Depending on your subject and your message, position the light in a way that makes it represent a certain time of day, or so it reveals something about your subject. For instance, place it low and to the side to mimic sunset lighting or to reveal the texture of a subject.
Address the quality of your light. The closer you move the light source to your subject, the softer it becomes, and the farther you move it from the subject the harder the light becomes. If you want to give the appearance of direct sun, consider moving the light out. Move it in closer to create the appearance of hazy light and even closer for cloudy light.
Create the intensity of light you want. Adjust the power on your flash or strobe to balance its intensity in regards to your ambient light. Setting the flash to be about three stops greater than the ambient light creates a realistic amount of contrast for direct sun conditions.
A light meter can measure your different light sources, but if you don’t have one, or don’t know how to use one, simply look at the camera’s LCD monitor to determine whether your key light needs to be turned up or down in power.
Consider the color of your light. If you simply wish to create a normal daylight look, use the custom white balance feature or set your camera’s white balance mode to flash.
If you’re going for a sunset look, try placing a warming gel over your flash or strobe to warm its color. This helps to mimic what actually happens as the sun passes through the Earth’s atmosphere at low angles.