How To Use Fill-In Flash

How To Use Fill-In Flash

by William Lulow

Here’s a little example of what a “fill-in” flash can do. A “Fill-In” light is basically a light that fills-in detail that the camera would not ordinarily see. Since our eyes are about 50 times more sensitive (just a guess) than any image-capturing device (film or CCD), we see more detail than these devices do. So, from time to time, we have to help our cameras “see” detail. We do this by adding fill-in light. Fill-in light shouldn’t overpower the ambient light. It should just brighten up the shadows a bit.

Here is an example:

This was an image made for the Association of Real Estate Women in New York City. I found a rooftop and positioned the subjects with their backs to the sun and used a fill-in flash to light all the faces. Note the very neat light on everyone’s heads. That really makes them stand out from the background.

Here’s another example of how Fill-In light works. The light on this subject was a Rembrandt Light coming from the left side of the camera and up high. It caused a shadow on the opposite side of the face.

In order to register detail in the shadow areas, a fill-in light was added on the shadow side. You don’t want the fill-in light to be as strong or stronger than the main light. If you do, you will have conflicting shadows that give the subject a very unnatural look. So, make sure that your fill-in light is weaker than the main light. This can be achieved by using a bulb of lesser wattage, dialing down the power on the fill-in light or moving the fill-in light further away from the subject. Sometimes the fill-in doesn’t have to be a light at all. It can be something like a reflector card that just throws more light to the part of the subject that is in shadow. This will only work if the reflector is on the opposite side of the subject than the main light source. 

Here is the same image without the fill-in light:

So, whenever you want to show more detail in your image, think of using a fill-in light.